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kakov
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Posted: Jan 13, 2014 18:22 Post subject: Collection of kakov |
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Strictly speaking I am not an active collector for the moment, but I do have stones and minerals around me from my previous periods I would like to share here; hope they add some value.
Today we start with three pieces from what I consider one of the most exciting localities of the world: the Ilímaussaq intrusive complex near Narsaq on South Greenland.
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Green Sodalite, Steenstrupine-(Ce) Ilímaussaq intrusion, Narsaq, S-Greenland 12 x 12 x 6 cm |
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44301 Time(s) |
![IMG_0858_2.JPG](files/img_0858_2_160.jpg)
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Steenstrupine-(Ce) xx Ilímaussaq intrusion, Narsaq, S-Greenland section from piece on the previous photo, crystals around 0,5 x 0,5 cm |
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44310 Time(s) |
![IMG_0855_2.JPG](files/img_0855_2_154.jpg)
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Steenstrupine-(Ce) in Lujavrite (name of the rock) Kvanefjeld, Ilímaussaq intrusion, Narsaq, S-Greenland 6 x 4 x 2,5 cm |
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![Steenstrupine-(Ce) xx in Lujavrite, Kvanefjeld, Greenland.JPG](files/steenstrupine_ce_xx_in_lujavrite_kvanefjeld_greenland_707.jpg)
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Epistolite, Ussingite Ilímaussaq Intrusion, Narsaq, S-Greenland 7 x 5 x 3 cm |
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44359 Time(s) |
![IMG_0860.JPG](files/img_0860_986.jpg)
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Mark Ost
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Posted: Jan 13, 2014 19:18 Post subject: Re: Collection of kakov |
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These rocks are interesting in that they may not be classical aesthetic samples sought by collectors, they are though spectacular UV specimens. If I am not mistaken, the Greenland government authorities may be limiting collection of these rocks and minerals.
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kakov
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Posted: Jan 14, 2014 14:08 Post subject: Re: Collection of kakov |
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Thanks for the comment Mark, you are completely right about the strong (and diverse) fluorescence of many stones form this locality. The green sodalite above exhibit spectacular bright orange FL under LWUV. Then many of the minerals (and rocks) there that are not even aesthetic under UV light posses “conceptual beauty” for minds eyes. Take the third photo above, the steenstupine-(Ce) xx in lujavrite (rock) from Kvanefjeld. Maybe a bit ugly, but it is representative of one of the three crystal forming habits of this complex phospho silicate. Steenstupine-(Ce) turned out to be a high quality ore for critical rare earth elements (plus uranium), the possibility of extraction from Kvanefjeld being currently in an advanced phase.
Lujavrite is the most fine grained of the alkaline rock types of the intrusion; with a 10x magnification you can see the structure: a compact matrix of mainly arfvedsonite needles and albite.
As an additional curiosity: due to the low silica content of these exotic rocks quartz has never been found inside the intrusion.
I brought this piece 25 years ago in Copenhagen.
Unfortunately I have never been up there, but from what I am told by friends my impression is similar to what Mark is commenting: without special permits collecting is restricted.
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kakov
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Posted: Jan 15, 2014 17:55 Post subject: Re: Collection of kakov - Charoites |
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We are leaving Greenland for now (coming back later in the string).
Today I would like to show some pieces with Charoite, a mineral occurring exclusively in the Murun alkaline complex in Yakutia, Russia. (more or less "around" the Lake Baikal.)
The word "Charoitite" designates the rock whose main component is Charoite - usually associated with Aegirine (dark green needles or sprays) and Tinaksite (yellow prisms) among other exotic stuff.
Most of the literature is in Russian and the free Google translator returns practically nonsense.
Fortunately we have an excellent work in English on the internet, with the only minus of the low quality pictures, but as for the content it is quite extensive:
Aspects of the mineralogy of the Murun alkaline complex, Yakutia, Russia. - by Ekaterina Reguir
Master thesis from de Lakehead University Thunder Bay, Ontario Canada, April 2001
https://www.collectionscanada.gc.ca/obj/s4/f2/dsk3/ftp04/MQ60867.pdf
(link normalized by FMF)
highlights from this source:
* The Murun complex was discovered in the end of the 1930ies - start 40ies by an expedition led by V G Ditmar.
* It has approx 150-180 Km2.
* The Charoite was discovered in 1949 and approved by the IMA in 1977 (Rogova et al. 1978)
* Mn2+ y Mn3+ are responsible of the characteristic colour.
* Four different Charoite bearing rocks have been identified, two of which has been commercially extracted.
* The article distinguish between eight different varieties of Charoite according to differences in texture.
* The process of building is still under debate. According to one of the theories it happened through metasomatism, some kind of contact metamorphism between alkaline magma and a sedimentary rock. In any case we talking about a rare event, with this chemistry it only occurred at this one single place on Earth.
Unfortunately I have seen very little rough material, almost everything on shows, internet and in museums is cut and polished - so is most of my pieces.
I am specially fascinated by the diversity of different structures in Charoite / Charoitite, this is one of the things what the next five photos try to reflect.
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Charoite, Aegirine, Tinaksite Murun alkaline complex , Sakha, Yakutia, Siberia, Russia 7 x 5 x 3 cm |
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44095 Time(s) |
![IMG_2185.JPG](files/thumbs/t_img_2185_787.jpg)
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Charoite, Aegirine, Tinaksite Murun Alkaline Complex , Sakha, Yakutia, Siberia, Russia 20 x 17 x 4 cm |
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44105 Time(s) |
![IMG_2197.JPG](files/thumbs/t_img_2197_812.jpg)
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Charoitite (Charoite and associated minerals) Murun Alkaline Complex , Sakha, Yakutia, Siberia, Russia section: 12 x 6,5 cm |
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44021 Time(s) |
![IMG_2190.JPG](files/thumbs/t_img_2190_499.jpg)
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Charoite, Aegirine Murun Alkaline Complex , Sakha, Yakutia, Siberia, Russia 10 x 3 x 3 cm |
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44080 Time(s) |
![IMG_2195.JPG](files/thumbs/t_img_2195_116.jpg)
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Charoite, Aegirine Murun Alkaline Complex, Sakha, Yakutia, Siberia, Russia 6 x 4 x 3 cm & 5 x 3 x 1,5 cm |
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44104 Time(s) |
![IMG_2196.JPG](files/thumbs/t_img_2196_136.jpg)
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kakov
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Posted: Jan 20, 2014 15:06 Post subject: Re: Collection of kakov - Alkaline Suite |
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Today I would like to share more pieces of typical minerals from the alkaline intrusive complexes of Ilímaussaq (near Narsaq on South Greenland) and from the geologically similar complexes Khibny and Lovozero on the Kola Peninsula in Russia.
Unfortunately the locality is not very specific for many of them (i.e. regarding exact proceeding from within the complexes); some of these pieces were acquired without label.
In the intention of improving the image quality I try to switch from natural light (used in my Spanish FMF album so far – all these pieces are already published there) to artificial light here, and on some pieces I reduce section area, showing less matrix, to focus on the mineral in question. Obviously there is still a lot of space for improvement, advices are much appreciated.
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Astrophyllite, Aegirine Khibiny Massif, Kola Peninsula, Russia 11 x 7 x 4,5 cm |
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43978 Time(s) |
![IMG_2250.jpg](files/thumbs/t_img_2250_156.jpg)
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Ussingite, Vuonnemite, Sphalerite 7 x 4,5 x 3 cm Lovozero Massive, Kola Peninsula, Russia Probably from the Shkatulka pegmatite - to be confirmed. The purple material is the Ussingite; they yellow plate on the top is Vuonnemite, Sphalerite is seen as bright yellow grains in the Ussingite. The small black dots might be Steenstrupine-(Ce), that is much less common in the Kola intrusions than in Ilímaussaq. |
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43944 Time(s) |
![IMG_2239.JPG](files/thumbs/t_img_2239_194.jpg)
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Eudialyte Kola Peninsula, Rusia 9 x 6 x 4 cm The other side of the same piece (with dark matrix) on the next photo.
This is one of the classic minerals of alkaline sites. It looks like garnet but have a completely different composition and structure, its hardness is also considerably lower than garnet. |
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43955 Time(s) |
![IMG_2236.JPG](files/thumbs/t_img_2236_132.jpg)
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Eudialyte Kola Peninsula, Rusia 9 x 6 x 4 cm The other side of the same piece (with light matrix) on the previous photo.
This is one of the classic minerals of alkaline sites. It looks like garnet but have a completely different composition and structure, its hardness is also considerably lower than garnet. |
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43950 Time(s) |
![IMG_2237.JPG](files/thumbs/t_img_2237_557.jpg)
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Titanite Kola Peninsula, Russia section: 5 x 5 cm (entire piece: 7 x 5 x 4 cm - loaded in my album in the Spanish FMF) Not a specifically alkaline mineral, but in a pretty unusual habit. |
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43933 Time(s) |
![IMG_2232.JPG](files/thumbs/t_img_2232_152.jpg)
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Chkalovite, Tugtupite, Sorensenite, Analcime, Aegirine Ilímaussaq Intrusive Complex, Narsaq, Greenland 9 x 8 x 4 cm
The piece is slightly wet and it has been irradiated with SWUV right before the shot to enhance the visibility of Tugtupite.
This is a fragment of a hydrothermal vein with representation of typical silicates from the site; the first three are beryllium containing. The Tugtupite here is secondary, it is formed through transformation of Chkalovite, hence it is not very pure nor deep in color, nevertheless it is strongly fluorescent under UV (LW and SW) Sorensenite is the curved prisms on the border above of the big Tugtupite/Chkalovite grain. Analcime appears as round grains on the top, while most of the dark areas in the piece are fine needles of Aegirine. In the Ilímaussaq string of the Spanish FMF you can see photos of the same stone in dry state and the Tugtupite almost colorless after long time in the dark; in the same string there is also a LWUV photo of it. |
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44016 Time(s) |
![IMG_2245.JPG](files/thumbs/t_img_2245_115.jpg)
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Chkalovite, Tugtupite Ilímaussaq Intrusive Complex, Narsaq, Greenland (section 10 x 4 cm) Side view of the previous piece. This capture shows the typical appearance of the beryllium silicate Chkalovite: it has a luster somewhat similar to fresh cheese. |
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43933 Time(s) |
![IMG_2247.jpg](files/thumbs/t_img_2247_806.jpg)
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Tugtupite, Albite Ilímaussaq Intrusive Complex, Narsaq, Greenland max measurement: 3 cm These pieces small but show relatively good quality Tugtupite. They are all dry and have NOT been irradiated with UV right before the shot. |
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43991 Time(s) |
![IMG_2248.JPG](files/thumbs/t_img_2248_926.jpg)
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Aegirine section: 5 x 5 cm (entire piece: 13,5 x 9 x 3,5 cm - visible in Spanish FMF) Being thin needles the green colour is clearly perceived, sometime Aegirine looks black – but strike color will always be green. This is the typical pyroxene of many different kind of alkaline rocks. |
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43927 Time(s) |
![IMG_2243_2.JPG](files/thumbs/t_img_2243_2_667.jpg)
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prcantos
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Posted: Jan 20, 2014 17:55 Post subject: Re: Collection of kakov |
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Wow! Alkaline rocks contain so strange and beautiful minerals. Thank you for share them here.
_________________ Pablo Rodríguez Cantos
Λίθον˛ον απεδοκίμασαν˛οι οικοδομουντες |
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Mike Wood
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Posted: Jan 21, 2014 13:30 Post subject: Re: Collection of kakov |
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Impressive specimens Mr. Kakov ! It's great to be able to see large rare minerals grown together like this, and thank you for describing the different minerals in each specimen.
I am very interested in these alkaline intrusive rocks and their associated rare minerals.
The polished charoite from Murun Alkaline Complex ( IMG_2195.JPG ) is very beautiful indeed.
Sincerely, Mike
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kakov
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Posted: Jan 25, 2014 06:58 Post subject: Re: Collection of kakov - Alkaline Suite, Part II. |
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Many thanks Pablo and Mike for your appreciation; it is great to receive feedback!
Today’s alkaline program is the following: We start on the Kola Peninsula (Russia) to see Murmanite. The most of the rest of this post will contain pieces from Ilímaussaq (Greenland), where we will see Naujakasite, Arfvedsonite, Eudialyte, Aegirine, Neptunite, Nepheline and more Tugtupite. We end up with a small homage to Mont Saint-Hilaire, the famous Canadian brother-site with a piece of Eudialyte from there.
Like every specimen shown so far in this string the ones today will also be all macros, taken with Canon PowerShot SX240 HS camera and a lamp.
Description: |
Murmanite Peninsula Kola, (probably the Lovozero Massif), Russia FoV= 4 x 3 cm; crystal: 1,5 x 0,5 cm
MURMAINTE is a titanium and niobium containing sorosilicate, closely related in composition and structure with Epistolite and Vuonnemite, both of which are already pictured above in the this string. On fresh surfaces the he color is more pinkish than here. I would like to highlight the lustre of this mineral, subtle and difficult to describe, mindat calls it “greasy, pearly” other sources use the wording “silverlike”. Altogether this is a good reminder of the diversity of lustres in the mineral kingdom that we should experience directly and not only through the limited expressions for lustre in language.
As for the genesis, Murmanite belongs to a category of minerals that are not crystallized from melts or solutions, but form exclusively by transformation of other phases. (Khomyakov library(.)iem(.)ac(.)ru(/)exper(/)v10_1(/)49(.)pdf) |
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43925 Time(s) |
![IMG_2259.JPG](files/thumbs/t_img_2259_123.jpg)
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Description: |
Arfvedsonite, Tugtupite, Albite Ilímaussaq Intrusive Complex, Narsaq, Greenland 4,5 x 3,5 x 3 cm Arfvedsonite is the typical amphibole of the intrusion. The best way to distinguish from Aegirine is through the strike colour that is more bluish for Arfvedsonite, while that of aegirine is clearly green-green. |
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43782 Time(s) |
![IMG_2275.JPG](files/thumbs/t_img_2275_142.jpg)
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Description: |
Naujakasite Ilímaussaq Intrusive Complex, Narsaq, Greenland FoV= 3 x 3 cm; Crystal: 1.5 x 1.2 cm
NAUJAKASITE is by no means an aesthetic mineral but it is deeply exciting conceptually, let us see why:
This string begins with two pieces of Steenstrupine, a mineral found only few places and in low quantities outside the Ilímaussaq Intrusion. It has very complex structure and around 20 different elements in the full formula, many of which are rare ones. The Naujakasite is similar in distribution, it is practically never found at all outside the Intrusion, even if inside it is locally very common, it reach to be the main component of a rock. But in opposition to Steentrupine, its formula is surprisingly simple: Na6(Fe,Mn)Al4Si8O26 Now, in case of “strange combination of weird elements” we somehow “intuitively” accept that the formation event has been a rare one with only one or very few known occurrences on Earth. Nevertheless seeing such a simple formula with few and common elements, the uniqueness of the Ilímaussaq formation is somehow even more striking.
Strongly simplified, apart from the presence of many rare elements we are talking about a magma with very low concentrations of silicium (quarz is never found in most of the area in the central parts of the Intrusion!) and very high concentrations of sodium (Na) – an element present in high amounts in many Ilímaussaq minerals. (no wonder Sodalite has its type locality here…) |
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43732 Time(s) |
![IMG_2272.JPG](files/thumbs/t_img_2272_878.jpg)
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Tugtupite, Pyrochlore, Neptunite Ilímaussaq Intrusive Complex, Narsaq, Greenland 9 x 4 x 2 cm (irradiated with SWUV before the shot)
Focus on relevant area and comments to Neptunite and Pyrochlore on the next pic. |
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43804 Time(s) |
![IMG_2273.JPG](files/thumbs/t_img_2273_150.jpg)
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Description: |
Pyrochlore, Neptunite, Tugtupite Ilímaussaq Intrusive Complex, Narsaq, Greenland FoV: 5 x 3 cm Section from piece on previous photo. Here the Pyrochlore is clearly visible as the greasy yellow irregular string and spots in the middle. There are deep red Neptunite grains inside, but this mineral is more clear on the piece of next pic
NEPTUNITE is a relatively common mineral in some rocks of the Ilímaussaq complex, among them the beryllium bearing hydrothermal veins. Hence if you have Tugtupite in your collection on a relatively decent sized matrix, it is highly probable you also will have Nepunite in it somewhere. We are not talking about showy crystals like the well known wonders from San Benito, California, the grains/crystals here seldom get over a few mm and they are usually surrounded by other minerals. Nevertheless the Ilímaussaq Neptunite has some really interesting features, of which I would highlight: 1) It always shows the deep red colour. 2) Association: in the Tugtupite bearing hydrothermal veins the Neptunite grains are almost always directly associated with the niobium mineral Pyrochlore, that forms yellow or light brown irregular spots or oblong areas with a greasy lustre. Inside or near this substance we have dark grains, clearly deep red with a 10x loupe and often of romoidal shape – this is the Neptunite! 3) Cultural aspects: Although the type locality is not Ilímaussaq rather the Narsarsuk pegmatite located in the Igaliko intrusive complex, the two locations are relatively close to each other (and type locality Neptunite is practically impossible to get!). Furthermore we can say that the name given to the mineral is somehow equally justified at this site: In the Narsarsuk pegmatite there are big amounts of Aegirine, named after the sea god Aegir in the Nordic mythology – this association inspired the usage of “Neptun”, the Roman sea god in the nomenclature of the associated mineral. And well, Aegirine is also a common mineral in the Ilímaussaq complex… |
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43756 Time(s) |
![IMG_2274.JPG](files/thumbs/t_img_2274_575.jpg)
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Description: |
NEPTUNITE, Pyrochlore, Tugtupite Ilímaussaq Intrusive Complex, Narsaq, Greenland FoV: 4 x 5 cm (for reference you have the curvature of my finger on the top) section of Neptunite crystal in right down corner: 3 x 3 mm
I have taken this piece for the relatively well developed Neptunite crystals (NB! this is not a micro photo), the Pyrochlore is more visible in the previous piece, here there are only small spots of it to the right of the central Neptunite area. The Tugtupite is also of very bad quality.
NEPTUNITE is a relatively common mineral in some rocks of the Ilímaussaq complex, among them the beryllium bearing hydrothermal veins. Hence if you have Tugtupite in your collection on a relatively decent sized matrix, it is highly probable you also will have Nepunite in it somewhere. We are not talking about showy crystals like the well known wonders from San Benito, California, the grains/crystals here seldom get over a few mm and they are usually surrounded by other minerals. Nevertheless the Ilímaussaq Neptunite has some really interesting features, of which I would highlight: 1) It always shows the deep red colour. 2) Association: in the Tugtupite bearing hydrothermal veins the Neptunite grains are almost always directly associated with the niobium mineral Pyrochlore, that forms yellow or light brown irregular spots or oblong areas with a greasy lustre. Inside or near this substance we have dark grains, clearly deep red with a 10x loupe and often of romoidal shape – this is the Neptunite! 3) Cultural aspects: Although the type locality is not Ilímaussaq rather the Narsarsuk pegmatite located in the Igaliko intrusive complex, the two locations are relatively close to each other (and type locality Neptunite is practically impossible to get!). Furthermore we can say that the name given to the mineral is somehow equally justified at this site: In the Narsarsuk pegmatite there are big amounts of Aegirine, named after the sea god Aegir in the Nordic mythology – this association inspired the usage of “Neptun”, the Roman sea god in the nomenclature of the associated mineral. And well, Aegirine is also a common mineral in the Ilímaussaq complex… |
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43897 Time(s) |
![IMG_2255.JPG](files/thumbs/t_img_2255_184.jpg)
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Description: |
Eudialyte, Aegirine, Nepheline, Feldspar Ilímaussaq Intrusive Complex, Narsaq, Greenland FoV: 4 x 3,5 cm polished Nepheline is commented on the next pic |
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43758 Time(s) |
![IMG_2282.JPG](files/thumbs/t_img_2282_209.jpg)
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Description: |
Nepheline (?), Aegirine Ilímaussaq Intrusive Complex, Narsaq, Greenland FoV: 5 x 4 cm (side view of the piece on the previous photo) Formation of Nepheline shows the lack of silicium in the magma. It can be difficult to distinguish from feldspar, as it has similar colur and hardness, but it lack clear cleavage and has a somewhat greasy lustre - I am almost sure most of the gray substance we see here is nepheline. (in other areas of the same stone there is also a bit of feldspar, see previous pic) |
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43734 Time(s) |
![IMG_2287.JPG](files/thumbs/t_img_2287_110.jpg)
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Description: |
Eudialyte, Aegirine Mont Saint-Hilaire, Canada 4,5 x 4 x 4 cm Many of the minerals originally described from Ilímaussaq or the Kola complexes were later also reported from Mont Saint-Hilaire, although I have the impression that mostly in micros.
I highly recommend the album of Doug Merson here in the FMF where we have many gorgeous micros from there. |
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43701 Time(s) |
![IMG_2266.JPG](files/thumbs/t_img_2266_132.jpg)
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Posted: Jan 26, 2014 17:00 Post subject: Re: Collection of kakov |
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Thanks again for your photo's and detailed descriptions and information!
This is great for learning
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Don Lum
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Posted: Jan 26, 2014 17:30 Post subject: Re: Collection of kakov |
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Thanks for your fine photographs and descriptions.
I like your charoite specimens. Nice !!!
Don
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kakov
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Location: Madrid
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Posted: Feb 03, 2014 15:00 Post subject: Re: Collection of kakov - Narsarsukite |
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Thanks a lot Mike and Don!
Today I would like to show two very different kinds of narsarsukite from South Greenland; one from the Ilímaussaq Complex the other from a dyke on a small island right beside Narsaq, but a bit outside the Complex.
Many North American collectors might be familiar with the mineral from their latitudes, as it also occurs at Mont Saint-Hilaire, Canada, and at several sites in the US.
The empirical formula is similar to neptunite but has a different crystal structure.
More info gathered and organized is attached to the photos.
Description: |
Narsarsukite, Manganoan Pectolite (black) Kangerdluarsuk, Ilímaussaq Intrusive Complex, Narsaq, Greenland FoV: 2,5 x 2 cm
GENERAL about the mineral: * Narsarsukite is a titanium containing chain silicate known currently from around 20 alkaline localities worldwide. * General formula is Na2(Ti,Fe)Si4O11 - may contain F and OH * Tetragonal, seen mostly as tabular crystals, parallel to {oo1}. * NOTE: Neptunite has almost identical formula but different crystal structure; it has monoclinic crystals. * usually the color is YELLOW * The type locality is the Narsarsuk pegmatite from where the mineral was described by the Swedish mineralogist Flink in 19O1.
Ilímaussaq Narsarsukite: * First described from the Ilímaussaq complex by the Russian mineralogist Semenov in 1969 * Occurs in a quartz-bearing contact zone between naujaite and alkaline granite * This environment is in accordance with: * "Requisite conditions for narsarsukite growth may be obtained where emanations from alkaline magmas react with siliceous wallrocks" (Stewart (1959), quoted in UPTON et. al. 1977)
* The piece on this photo is from Kangerdluarsuk; where we are near the southern border of the Complex.
Turkestanite: There are brown prisms (not very much darker than the narsarsukite) in the piece that is turkestanite (pointed out by a trustworthy source who had the piece in his hands). Not very well visible on this view, but there is the squared cross section of a crystal approx in the middle, above the left corner of the long narsarsukite plate. Other day I will try take and load close ups where it is better seen. * "Ilimaussaq turkestanite forms up to a few millimeter large, brown or brownish-orange, idiomorphic, simple prismatic crystals; associated minerals are microcline, albite, augite, aegirine, quartz eudialyte and narsarsukite." (PETERSEN et.al 1999)
refs: * STEWART 1959. Narsarsukite from Sage Creek, Sweet Grass Hills, Montana. Amer. Min. 44, 265-73. (as quoted in: UPTON et. al. : Narsarsukite - a new occurrence in peralkaline trachyte, south Greenland - Mineralogical Magazine, Sept 1976, Vol. 40 PP. 737-46 www.minersoc.org/pages/Archive-MM/Volume_40/40-315-737.pdf)
* PETERSEN et.al: Turkestanite from the Ilímaussaq alkaline complex, South Greenland Neues Jarhrbuch für Mineralogie - Monatshefte, issue: 9, 1999, pp: 424 - 432 (I did not manage to get the entire article, above sentence is quoted from the abstract) |
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![IMG_2355.JPG](files/thumbs/t_img_2355_102.jpg)
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Description: |
Narsarsukite Island of Igdlutalik, Narsaq, South Greenland FoV: 2,5 x 2 cm
GENERAL info about the mineral: * Narsarsukite is a titanium containing chain silicate known currently from around 20 alkaline localities worldwide. * General formula is Na2(Ti,Fe)Si4O11 - may contain F and OH * Tetragonal crystal forms, mostly plates * NOTE: Neptunite has almost identical formula but different crystal structure; it has monoclinic crystals. * The type locality is Narsarsuk (xxx complex) from where the mineral was described by the Swedish mineralogist Flink in 19O1.
My previous photo of Narsarsukite from Ilímaussaq show a more typical aspect of the mineral, i.e. yellow plates. The following is information about the PARTICULAR Igdlutalik Narsarsukite on this photo (source in the end):
The SITE : * Igdlutalik is NOT inside, rather 12 km west of the Ilimaussaq complex. (and 45 km west of the type locality Narsarsuk) * Narsarsukite occurs at the island within a dyke of peralkaline trachyte. * The dyke was found during the 1 : 2o ooo reconnaissance mapping of the Julianehaab area by the Greenland Geological Survey. * It is some 20 m wide and the outcrop can be traced not more than 50 m along the length of the dyke.
The CRYSTALS of Igdlutalik Narsarsukite: * Short prisms (around twice as long as they are broad) unlike most narsarsukite from other locations that have tabular habits. * Forms {1oo} and {oo1} are dominant * The unique GREEN color here is probably due to aegirine inclusions. (the mineral itself is normally yellow)
COMPOSITION - particularities: * The Igdlutalik narsarsukite has a distinctly high Ti/Fe ratio compared with those from Ilimaussaq and Narssarssuk; in this respect it most closely resembles the Sweet Grass, Montana narsarsukites (Stewart, 1959). * Niobium is a significant minor component
FORMATION: * All known occurrences of narsarsukite are in silica-oversaturated environments in close association with alkaline intrusive rocks that have crystallized at relative low pressures. * Stewart (1959) pointed out that the requisite conditions for narsarsukite growth may be obtained where emanations from alkaline magmas react with siliceous wallrocks. * Growth of narsarsukite, according to Stewart (I959), requires an excess of silica, high partial pressure of oxygen, and all abundance of Ti and Na. Stewart considered that at lower oxygen pressure neptunite, Na2FeTiSi4O12, would be generated. However, Rajasekaran (I966) demonstrated the apparently stable coexistence of narsarsukite and neptunite at St. Hilalre, Quebec.
SOURCE OF INFORMATION - most of the above is directly extracted from: UPTON et. al. : Narsarsukite - a new occurrence in peralkaline trachyte, south Greenland Mineralogical Magazine, Sept 1976, Vol. 40 PP. 737-46 www.minersoc.org/pages/Archive-MM/Volume_40/40-315-737.pdf (giving all the references I have left in the above extracts)
on Mindat: * Igdlutalik, the locality : http://www.mindat.org/loc-23311.html (by the way it is the type locality for Emeleusite) * Narsarsukite crystals from the same dyke http://www.mindat.org/locentry-156911.html |
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kakov
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Posted: Feb 15, 2014 08:39 Post subject: Re: Collection of kakov - Ytterby etc. |
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Today I´d like to show a few Scandinavian pieces with REE (and other "funny") elements from historical sites. To compensate for being so ugly I also include a small Norwegian ruby form the classic Froland site.
Finally one more photo of an other Naujakasite from Ilímaussaq where the colour is better than on the one I showed before.
Description: |
Fergusonite-(Y), Feldspar Biotite Ytterby, Vaxholm, Sweden FoV: 4 x 4 cm One more ugly mineral that nevertheless is exciting. First the exotic formula, it is a niobate of yttrium (YNbO4) Then the locality is hardcore: It is a historical Swedish quarry that has delivered material for the discovery of 10 different rare earth elements - four of which have names derived directly from the place itself: Yttrium, Terbium, Erbium, Ytterbium
about the site: http://www.mindat.org/loc-3191.html |
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![IMG_2364.JPG](files/thumbs/t_img_2364_322.jpg)
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Thalenite-(Y), Tengerite-(Y) Åskagens kvartsbrott, Värmland, Sweden FoV: 3 x 3 cm A silicate and a carbonate of Yttrium.
the site: http://www.mindat.org/loc-10006.html |
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![IMG_2382.JPG](files/thumbs/t_img_2382_174.jpg)
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Description: |
Gadolinite Ytterby, Vaxholm, Sweden FoV: 5 x 3 cm Not a too good piece, but gadolinite from this historical Swedish quarry was the most important mineral for the discovery of most of the 10 different rare earth elements - four of which have names derived directly from the place itself: Yttrium, Terbium, Erbium, Ytterbium
the site: http://www.mindat.org/loc-3191.html |
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![IMG_2390.JPG](files/thumbs/t_img_2390_147.jpg)
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Description: |
Thortveitite Kabuland, Iveland, Norway 14 x 11 x 9 mm A silicate of the rare element scandium Found in 1989 by Frode Andersen. Brought in June 1991 at the Koppaberg show (Sweden), an amazing event in the middle of a forest. |
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![IMG_2388.JPG](files/thumbs/t_img_2388_139.jpg)
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Description: |
Thortveitite Kabuland, Iveland, Norway 14 x 11 x 9 mm A silicate of the rare element scandium Found in 1989 by Frode Andersen. Brought in June 1991 at the Koppaberg show (Sweden), an amazing event in the middle of a forest. |
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![IMG_2379.JPG](files/thumbs/t_img_2379_171.jpg)
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Corundum (Ruby) Froland, Norway FoV: 3 x 3 cm |
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![IMG_2367.JPG](files/thumbs/t_img_2367_141.jpg)
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Description: |
Corundum (Ruby) Froland, Norway FoV: 3 x 3 cm |
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![IMG_2368.JPG](files/thumbs/t_img_2368_191.jpg)
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Description: |
Naujakasite Ilímaussaq Intrusive Complex, Narsaq, Greenland FoV: 2,5 x 2 cm A strange mineral that formed instead of nepheline in certain parts of the hyper-agpaitic magma (=low silica, high sodium) of the Ilímaussaq Intrusion. In spite of not containing any rare elements, it is practically not found anywhere else on Earth. More info above my other Naujakasite photo that shows a single crystal. On this piece the colour is more fresh, greenish. |
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![IMG_2372.JPG](files/thumbs/t_img_2372_444.jpg)
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kakov
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Posted: Aug 18, 2015 12:52 Post subject: Re: Collection of kakov - Stichtite |
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Stichtite is an interesting carbonate mineral. Worldwide occurrences were documented at 14 different localities in 1997 and 42 in 2012. I don´t know the reason for such a heavy increase in just 15 years, but it could be related to the general excitement around serpentine and serpentinization after the discovery of the Lost City ultramafic-hosted hydrotermal system on the Atlantic seabed around 2000 - which is probably a key for our understanding of the emergence of life (on Earth and elsewhere). As we will see bellow, due to indirect reasons the Stichtite formation has also become a brick in this great puzzle.
The small piece I show here is from the "classic" area in Tasmania.
Stichtite is a transformation product of a serpentine mineral, probably lizardite. The process is an abiological carbonation of serpentine, probably by methane, in the presence of chromium.
The black dots inside the purple substance on bellow photo are probably the Cr source mineral (probably Cr-spinel or cromite).
The photo is taken with the piece under water to enhance the visibility of these black dots.
Stichtite is very soft and it has never been found as crystals.
Info from freely available parts of:
L. D. Ashwal & B. Cairncross: Mineralogy and origin of stichtite in chromite-bearing serpentinites
Contributions to Mineralogy and Petrology, March 1997, Volume 127, Issue 1-2, pp 75-86
link(dot)springer(dot)com/article/10.1007/s004100050266#page-1
E. Melchiorre & A Lopez: Carbon and Hydrogen Isotope Values of Fluids within Methane-rich Serpentinizing Environments of Early Earth: Evidence from Stichtite
Astrobiology Science Conference 2012, Poster Session
https://abscicon2012.arc.nasa.gov/abstracts/abstract-detail/carbon-and-hydrogen-isotope-values-of-fluids-within-methane-rich-serpentinizing-environments-of-early-earth-evidence-from-stichtite/
What I consider key quotes from the second article (Melchiorre & Lopez):
• “Results of carbon and hydrogen stable isotope analyses of Tasmanian and South African stichtites show values consistent with formation in an abiogenic, serpentinizing environment. The isotope values show that it is unlikely that the stichtite received C and H from a source that was in equilibrium with the atmosphere, or a biological source. “
• “Mineral geochemistry, ion microprobe data, cross-cutting relationships, and C-H isotope values all suggest that stichtite formation is associated with methane rich Alpine-type serpentinizing environments, and that stichtite is not a weathering product of chromites within the oxidation zone. “
• “It is likely that stichtite has fairly faithfully recorded the isotopic signature of methane in ancient serpentinizing environments from the Archean (South Africa) and Cambrian (Tasmania). This bears directly upon the study of early Earth environments, and the differentiation of biological vs. abiological signals in the rock record on Earth and other bodies of the solar system. “
(and for those interested in the big lines of the life-emergence story mentioned above:)
Othmar Müntener: Serpentine and serpentinization: A link between planet formation and life
https://geology.gsapubs.org/content/38/10/959.full
(links normalized by FMF)
Mineral: | Stichtite in serpentine (lizardite?) |
Locality: | Dundas, Zeehan District, West Coast Council, Tasmania, Australia | ![](templates/FabreMinerals/images/LocalidadesGreen.png) |
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Dimensions: | 3 x 2 x 0,7 cm |
Description: |
under water
comments to the mineral in "Collection of kakov" string, Aug 18th 2015 |
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![Stichtite in serpentine.JPG](files/thumbs/t_stichtite_in_serpentine_111.jpg)
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kakov
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Posted: Feb 21, 2018 13:53 Post subject: Re: Collection of kakov - Eudyalite |
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EUDIALYTE is one of my favorite minerals. In the following I would like to say a few words about its exciting history, composition and distribution.
In main lines I will re-use (semi-translate) what I have written last year for the Spanish FMF ( La Intrusión Alcalina de Ilímaussaq (Groenlandia) - (106) )
The Ilímaussaq intrusion near Narsaq on south Greenland is the type locality, where it is an important rock building mineral. Locally it can be common, but on world wide scale it is fairly rare. Also, it must be noted that even if masses and ingrown crystals are locally abundant, freely grown crystals with visible faces above a certain size are relatively complicated to get.
The mineral has been collected first time by Karl Ludwig GIESECKE (1761 - 1833) a super interesting character; before becoming an influential (amateur) mineralogist and polar explorer he was actor in Vienna. He was trapped on Greenland for many years due to the Napoleonic wars; the minerals he gathered during these years were later distributed throughout Europe.
He collected eudialyte at his two pioneering visits to Ilímaussaq in 1806 and 1809, nevertheless he took it for garnet. Thomas ALLEN (1777 – 1833), the Scottish mineralogist who made the initial review of the material repeated the error, although he wondered about the form of the crystals.
The German chemist Friedrich STROMEYER (1776 - 1835) has the honor of the identification and description as a new mineral in 1819, two years after having discovered cadmium, for which this scientist is mostly remembered. The name he has chosen for our mineral indicates the profession of the discoverer, it is based on a chemical property: the ease to dissolve in acids. It is composed by the Greek "eu"= "well" and "dialyein" = " decompose”. The pieces for the analysis and description proceeded from the material collected by Giesecke on his above-mentioned trips.
Truly speaking the only character that is similar to garnet is the color; both the composition, internal structure, crystal symmetry and physical properties of eudialyte are completely distinct from garnet! (Once again let us remember the importance of not being blinded by the most often unreliable trait of color in the mineral world…) The composition is a cyclosilicate of Na, Ca, Fe and Zr. It shows considerable variation among different deposits, some of which has been reflected in a broad spectrum of distinct interrelated minerals, the so called “eudialyte group”, whose complexity is steadily increasing. (it is worth to have a quick look at the members and their formula: https://www.mindat.org/min-11021.html ). We even have a sub-committee inside the IMA in charge of the nomenclature inside this group.
The structure has been established simultaneously but independently by two different group of researchers in 1971 (Giuseppetti et al & Golyshev et al). It is a unique combination of rings with three and nine SiO4 tetrahedrons. You can see gorgeous images of the structure in the Johnsen et. al. articles indicated below.
The crystals are trigonal. In Mindat you can see idealized drawings of two very distinct types, bellow I am trying to show these on my pieces.
The hardness is considerably lower than those of the garnets, only 5-6 on the Mohs scale. The color varies between different tones of reddish and brownish; until certain degree I think it is characteristic of the deposit the piece comes from.
Some of the eudialyte colors can be similar to some tugtupite colors, they are quickly distinguished under UV light: tugtupite will always have some fluorescence, eudialyte never.
Illustrations: Above in this string I am showing several massive pieces, where you can observe some of the variety in shades and paragenesis. Today I will show two crystals, corresponding to the mentioned two main types, see drawings in Mindat.
Sources and recommended further reading:
* Ole V. Petersen & Karsten Secher: The Minerals of Greenland. – Mineralogical Record Vol. 24, Nr 2. March-April 1993. pages 18-28 are about Ilímaussaq.
* O. Johnsen et al: The eudialyte group: a review www(dot)geus(dot)dk/publications/bull-gl/nr190/nr190_p065-072(dot)pdf
* O. Johnsen et. al: THE NOMENCLATURE OF EUDIALYTE-GROUP MINERALS: www(dot)crystallography(dot)fr/cims/pdf/EudialyteCanMin41-785(dot)pdf
Mineral: | Eudialyte |
Locality: | Ilímaussaq complex, Narsaq, Kujalleq, Greenland | ![](templates/FabreMinerals/images/LocalidadesGreen.png) |
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Dimensions: | FoV 2 x 2 cm |
Description: |
(extensive comments to the mineral in "Collection of kakov" string) |
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![Greenland-eudialyte1.jpg](files/thumbs/t_greenland_eudialyte1_158.jpg)
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Mineral: | Eudialyte |
Locality: | Eveslogchorr Mountain, Khibiny Massif, Kola Peninsula, Murmanskaja Oblast, Northern Region, Russia | ![](templates/FabreMinerals/images/LocalidadesGreen.png) |
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Dimensions: | crystal: 1,5 x 1,5 x 0,7 cm |
Description: |
(extensive comments to the mineral in "Collection of kakov" string) |
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![Kola-Eudyalite1.jpg](files/thumbs/t_kola_eudyalite1_697.jpg)
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Mineral: | Eudialyte |
Locality: | Eveslogchorr Mountain, Khibiny Massif, Kola Peninsula, Murmanskaja Oblast, Northern Region, Russia | ![](templates/FabreMinerals/images/LocalidadesGreen.png) |
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Dimensions: | crystal: 1,5 x 1,5 x 0,7 cm |
Description: |
(extensive comments to the mineral in "Collection of kakov" string) |
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![Kola-Eudyalite2.jpg](files/thumbs/t_kola_eudyalite2_149.jpg)
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kakov
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Joined: 24 Jul 2013
Posts: 39
Location: Madrid
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Posted: Apr 03, 2018 08:13 Post subject: Baryte, Uzbekistan |
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Apropos the gorgeous baryte collection of Mr. Brouwer, I would like to share a much humbler piece I acquired recently. The interesting is the relatively exotic origin (I have no other minerals from this country) and that it came with a small handwritten label with the full story of its origin. I like such personal details! Transcription of the label: “Baryte xls of two generations as result of penetration of BaCl2-CaCl2 brines into gypsum body in black schist. Contemporary formation. 30 km SE from Uch-Kuduk Kara-Kym desert Uzbekistan. Collected in 1993.”
Mineral: | Baryte |
Locality: | Uchquduq, Karakum Desert, Republic of Uzbekistan | ![](templates/FabreMinerals/images/LocalidadesGreen.png) |
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Dimensions: | 45 x 20 x 17 mm; 44 grams |
Description: |
Baryte xls of two generations as result of penetration of BaCl2-CaCl2 brines into gypsum body in black schist. Contemporary formation. 30 km SE from Uch-Kuduk Kara-Kym desert Uzbekistan. Collected in 1993. (by L.P.) |
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![Baryte, Uzbekistan.jpg](files/thumbs/t_baryte_uzbekistan_628.jpg)
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Mineral: | Baryte |
Locality: | Uchquduq, Karakum Desert, Republic of Uzbekistan | ![](templates/FabreMinerals/images/LocalidadesGreen.png) |
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Dimensions: | 45 x 20 x 17 mm; 44 grams |
Description: |
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![Baryte2, Uzbekistan.jpg](files/thumbs/t_baryte2_uzbekistan_107.jpg)
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Niels Brouwer
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Posted: Apr 03, 2018 13:51 Post subject: Re: Collection of kakov |
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Interesting locality indeed, I don't think I've come across one of these before.
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kakov
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Joined: 24 Jul 2013
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Location: Madrid
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Posted: Apr 08, 2018 11:45 Post subject: Radioactive fluorite and black cryolite |
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This is a fragment of the famous Ivigtut pegmatite.
We have an unusual fluorite: the red-brown concentric grains. It has a low content of the radioactive element thorium (Th).
The cryolite is normally white but darkens under the impact of radioactivity. Consequently, the color of the cryolite we see here is darker, practically black, close to the radioactive fluorite grains. It is lighter (only dark gray) in the center of the grains.
All the white in this piece is quartz.
Like in many Ivigtut pieces, we also see siderite (greenish brown rhombs, most obvious on the top).
The sulfides galena and chalcopyrite, also typical of the site, complete the panorama.
I´ve had this piece for over 20 years. Recently somebody has been so kind to cut it for me, whereby the constituting minerals got much clearer. I will soon get it polished. For this photo I simply put it under water.
Another piece with same paragenesis on Mindat: https://www.mindat.org/photo-324583.html
Mineral: | Cryolite (black), Fluorite (with Th), Siderite, Quartz, Galenite, Chalcopyrite |
Locality: | Ivigtut deposit, Ivittuut, Arsuk Fjord, Sermersooq, Greenland | ![](templates/FabreMinerals/images/LocalidadesGreen.png) |
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Dimensions: | FoV: 7 x 6 cm |
Description: |
commented in "Collection of kakov" string |
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![Black Cryolite, Th-Fluorite, , etc.jpg](files/thumbs/t_black_cryolite_th_fluorite__etc_201.jpg)
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