View previous topic :: View next topic |
Author |
Message |
Gail
Joined: 21 Feb 2008
Posts: 5839
Location: Texas, Lone Star State.
|
Posted: Apr 07, 2008 19:50 Post subject: Re: Gail's collection |
|
|
Here is a mineral that I bought from Jordi. I like it as much today as the first day I laid eyes on it. Jordi, this is your photo from when I first bought it, hope you don't mind that I use it?
Our catalog write up:
Aesthetic curving stack of lustrous 4mm cubic pyrite xls with several globular lenticular calcite xls
Description: |
Pyrite with Calcite Panasqueira, Covilha, Beira Baixa Minas da Panasqueira, Level 3. 3.4 x 5.0 x 1.5 cm |
|
Viewed: |
44591 Time(s) |
|
_________________ Minerals you say? Why yes, I'll take a dozen or so... |
|
Back to top |
|
|
Carles Curto
Joined: 14 Sep 2006
Posts: 160
Location: Barcelona
|
Posted: Apr 08, 2008 06:08 Post subject: Re: Gail's collection |
|
|
Most of analized samples of Kutnahorite from Kalahari are acicular crystals crossing Rhodochrosite, not easy to separate. Probably this kind of samples had some small Rhodochrosite impurities when they were analized. Kutnahorite and Rhodochrosite are quite different (chemical and structural) carbonates, difficult to confuse. Gail's especimen looks a very individualized white group and very probably it is just Kutnohorite.
|
|
Back to top |
|
|
Jordi Fabre
Overall coordinator of the Forum
Joined: 07 Aug 2006
Posts: 4897
Location: Barcelona
|
Posted: Apr 08, 2008 14:54 Post subject: Re: Gail's collection |
|
|
I'm afraid that I explained badly the Kutnohorite's analysis. Is not a Kutnohorite with traces of Rhodochrosite or something else, is a different case.
Joan Vinyals, an extremely good analyzer, used a pure "Kutnohorite" from Hotazel, very similar to the one of Gail, and he submited it first to a chemical analysis and then to a RDX prove, and for his (and my) surprise the result was not a Kutnohorite with traces of Rhodochrosite or a Rhodochrosite with traces of Kutnohorite but a combo of both species. We talked about it and the Joan's conclusion confirmed by other analysis, was that probably the majority of the "Kutnohorite" in fact are a mix of both species.
Again, this is not so important. Just a scientific curiosity to be commented, not much more.
Below you can see a copy of a RDX analysis of one "Kutnohorite"
Jordi
Description: |
|
Viewed: |
44383 Time(s) |
|
|
|
Back to top |
|
|
Pete Modreski
Site Admin
Joined: 30 Jul 2007
Posts: 709
Location: Denver, Colorado
|
Posted: Apr 08, 2008 16:49 Post subject: Re: Gail's collection |
|
|
Re. these kutnohorite (?) specimens, I have always been quite interested in these manganese carbonate minerals too. I had access "at my fingertips" (almost) to some of my own past X-ray diffraction patterns of these minerals from several localities--not including Hotazel, but it is helpful to compare them.
(P.S., before I continue--Gail, I have very much appreciated seeing all your specimen photos, you have some really interesting & great ones; and yours too, Tracy.)
Good that you had that X-ray pattern to share here, Jordi (in the U.S. we always call it XRD, so it wasn't much of a jump to figure out that's what your RDX meant). If it works to post this, I am going to repost a copy of your same pattern, with the peaks marked with a red or pink line to indicate those I would attribute to rhochrosite or kutnohorite respectively. (I hope the colors are distinguishable enough--I was using "MS Paint" for this and their palette didn't have a paler pink. It looks like Jordi's pattern had the two distinguished in black or gray, but those were pretty hard to tell apart.) The two minerals have most of the same diffraction lines, just shifted a bit. Anyway, what I see in this pattern is that the sample seems to be very predominantly rhodochrosite, with just a small amount of kutnohorite present--say maybe 5:1 or 10:1 (one can only take a rough guess).
These minerals differ a bit in their fluorescence under shortwave ultraviolet, so, Gail, if you have access to a UV light, it might be interesting to look at this specimen and report what you see. Generally, manganocalcite (manganoan calcite to use proper words) usually, but not always, fluoresces red, often very strong (localities differ; it probably depends on the trace elements other than Mn in the calcite); kutnohorite usually fluoresces weaker and sometimes not at all; and rhodochrosite, never. (It really needs someone to make some systematic observations on all these minerals from a variety of localities, especially of the kutnohorite, to be sure that these generalizations are correct!) So, though it would not tell anything positively, it would be interesting to hear what the UV response of your specimen is.
Pete Modreski
Description: |
Jordi's XRD pattern of his South Africa rhodochrosite(?); colored as to rhodo. vs. kutno. XRD lines |
|
Viewed: |
44363 Time(s) |
|
|
|
Back to top |
|
|
Gail
Joined: 21 Feb 2008
Posts: 5839
Location: Texas, Lone Star State.
|
Posted: Apr 08, 2008 17:51 Post subject: Re: Gail's collection |
|
|
When I was at the Smithsonian Museum of Nature and Science, a few weeks back, I watched Jeff Post do an analysis on a Hemimorphite, it was the same colour as many a Smithsonite and no one could be sure just by looking at it. The man who brought the specimen in invited me to watch how the equipment read his tiny bit of sample. It was a fascinating experience and I was mesmerized. And, just like the chart above, it had peaks and dips and I got to really see how it all came to the conclusion that it was, indeed, Hemimorphite and not Smithsonite although the owner was hoping for the latter.
So, i have a better understanding of how this all works.
I do believe we have a UV light around here somewhere, so must go see if I can dig it up and go on my adventure, like Nancy Drew. ( An American classic series of books about a young woman detective made popular in the 50's, 60's and beyond. )
On to my sleuth mission.....
_________________ Minerals you say? Why yes, I'll take a dozen or so... |
|
Back to top |
|
|
Gail
Joined: 21 Feb 2008
Posts: 5839
Location: Texas, Lone Star State.
|
Posted: Apr 08, 2008 21:50 Post subject: Re: Gail's collection |
|
|
To add to the fun of Tracy's fluorite EGG, I am posting one that I also enjoy and has a cast where a quartz crystal once was on the underside.
Description:
Wonderful ball fluorite ( without crystaline structure ), gossamer honey yellow translucent XL sphere ( 41 mm diameter ) on quartz bed, which is cast for terminal end of a large quartz past.
Photos by Gail Spann
Description: |
Same Fluorite, underside view. |
|
Viewed: |
44353 Time(s) |
|
Description: |
Fluorite ( yellow ball ) on Quartz Aurangabad, India 6.5 x 6.0 x 5.6 |
|
Viewed: |
44355 Time(s) |
|
_________________ Minerals you say? Why yes, I'll take a dozen or so... |
|
Back to top |
|
|
Gail
Joined: 21 Feb 2008
Posts: 5839
Location: Texas, Lone Star State.
|
Posted: Apr 08, 2008 22:13 Post subject: Re: Gail's collection |
|
|
One of my favourites of the Xenotime-(Y) specimens that we have in our collection.
Photo by Gail Spann
A rare Yttrium enriched brownish orange translucent elongated series of Xenotime-Y xls ( doubly terminated, with a perpendicular fully-terminated xl criss-crossing the topmost xl, possibly twinned? )
53 x 14 x 12 mm streched out along the face of a crumbly tan matrix block streaked with black ( Including some metallic prismatic xls ) with a smaller ( 12 x 9 x 5 mm ) doubly terminated xenotime-Y xl beside the end of the xenotime-Y xl series.
Description: |
Xenotime-(Y) Hammedabad, Khaffor Dehri, North West Frontier Province Zagi Mtn, Pakistan 7.6 x 6.5 x 6.8 cm. |
|
Viewed: |
44375 Time(s) |
|
_________________ Minerals you say? Why yes, I'll take a dozen or so... |
|
Back to top |
|
|
Gail
Joined: 21 Feb 2008
Posts: 5839
Location: Texas, Lone Star State.
|
Posted: Apr 08, 2008 22:23 Post subject: Re: Gail's collection |
|
|
I LOVE mimetite, no two ways about it...I think it is such a beautiful colour and this is one of many that I have in my collection. This is my "snail", not to steal the name from Bill Larson's N'Chwaning Rhodo, but this is a different mineral altogether.
This is a fairly new addition to my Mimetite suite.
Photo by Gail Spann
Description: |
Mimetite Congreso-Leon Mine San Pedro Corralitos, Chihuahua Mexico. 7.0 x 6.1 x 2.6 |
|
Viewed: |
44327 Time(s) |
|
_________________ Minerals you say? Why yes, I'll take a dozen or so... |
|
Back to top |
|
|
Gail
Joined: 21 Feb 2008
Posts: 5839
Location: Texas, Lone Star State.
|
Posted: Apr 08, 2008 22:33 Post subject: Re: Gail's collection |
|
|
Another CAST that really caught my eye in Tucson this year.
I call it the reverse "7" It really is a very different piece but one that I am quite fond of.
Gaudefroyite on Andradite cast after Hematite.
N'Chwaning Mine
Kuruman, Cape Province,
South Africa
Photo by Gail Spann
Description: |
back view... Gaudefroyite on Andradite cast after Hematite. N'Chwaning Mine Kuruman, Cape Province, South Africa 6.5 x 10.5 x 4.5 cm |
|
Viewed: |
44324 Time(s) |
|
Description: |
Gaudefroyite on Andradite cast after Hematite. N'Chwaning Mine Kuruman, Cape Province, South Africa 6.5 x 10.5 x 4.5 cm |
|
Viewed: |
44318 Time(s) |
|
_________________ Minerals you say? Why yes, I'll take a dozen or so... |
|
Back to top |
|
|
GneissWare
Joined: 07 Mar 2008
Posts: 1287
Location: California
|
Posted: Apr 15, 2008 10:06 Post subject: Re: Gail's collection |
|
|
Hi Gail,
It's been a week since our last mineral fix ;=)
Y'all going to post some new photos and stories? I have really enjoyed them.
Bob
|
|
Back to top |
|
|
Tracy
Joined: 15 Sep 2006
Posts: 551
Location: Toronto
|
Posted: Apr 15, 2008 10:34 Post subject: Re: Gail's collection |
|
|
I've got more photos to post, if people want to see them too...?
_________________ "Wisdom begins in wonder" - Socrates |
|
Back to top |
|
|
Jordi Fabre
Overall coordinator of the Forum
Joined: 07 Aug 2006
Posts: 4897
Location: Barcelona
|
Posted: Apr 15, 2008 11:04 Post subject: Re: Gail's collection |
|
|
Please!
Jordi
|
|
Back to top |
|
|
Gail
Joined: 21 Feb 2008
Posts: 5839
Location: Texas, Lone Star State.
|
Posted: Apr 16, 2008 14:22 Post subject: Re: Gail's collection |
|
|
Malachite pseudo. after Azurite ( sceptered ) with Cuprian Smithsonite.
Huge fully terminated chisel point azurite xls to 70 mm pseudomorphed into malachite with very lustrous feathered fans of multiple shades of green; one large 72 mm xl is sceptered with a second generation azurite xl on top of the first , which is not as far along in the ps. process; a third generation of gemmy gren cuprian smithsonite covers most of one side. This piece has many appreciative admirers. Put me at the top of the list. It is gorgeous from any angle and we display it in a cabinet with clear glass all around to enjoy it from wherever we sit. This is one of those "Killer" rocks that come along so infrequently.
Description: |
Malachite pseudomorph after Azurite ( sceptered ) with Cuprian Smithsonite Tsumeb Mine, Ojikoto Region, Namibia 12.7 x 10.7 x 7.7 cm |
|
Viewed: |
43954 Time(s) |
|
_________________ Minerals you say? Why yes, I'll take a dozen or so... |
|
Back to top |
|
|
Gail
Joined: 21 Feb 2008
Posts: 5839
Location: Texas, Lone Star State.
|
Posted: Apr 16, 2008 14:35 Post subject: Re: Gail's collection |
|
|
We bought this along about the same time as our "Leaning towers of Shigar" plate that was in our Desautels competition case in Tucson.
It is a pair of thick beautiful aqua blue stepped towers with tansparent top halves and milky bottoms on albite xl matrix.
This has been a great segway into talking about the growth of crystals to our grandchildren.
Description: |
Beryl var. Aquamarine on Albite Shigar, Baltistan, Northern Areas, Pakistan 10.2 x 10.7 x 7.0 cm |
|
Viewed: |
43928 Time(s) |
|
_________________ Minerals you say? Why yes, I'll take a dozen or so... |
|
Back to top |
|
|
Gail
Joined: 21 Feb 2008
Posts: 5839
Location: Texas, Lone Star State.
|
Posted: Apr 16, 2008 14:49 Post subject: Re: Gail's collection |
|
|
A truly colourful and exquisite Kunzite with gemstone, we find ourselves adding more "rough and cut" displays in our collection. We will have a base made for just the mineral and another for the mineral and gemstone. This way we have option for displaying one or both.
I need to look up the gemstone, so bear with me till I find that info then will include in this thread. I have a seperate list for those.
Elongated Kunzite xls ( 106 x 28 x 22 mm ) with pink to deep purple dichroism and multiple xl blases grown together to form a common long glassy xl edge "face" and a somewhat frosted opposite edge "face" with clean striated faces on both sides. Each crystal is fully terminated with lustrous "rooftop" peaked terminations.
The colour is really deep and that is why we displayed it with the cut stone.
Description: |
Spodumene var. Kunzite Mawi, Nuristan, Laghman Prov. Afghanistan 3.0 x10.6 x 2.2 cm |
|
Viewed: |
43952 Time(s) |
|
_________________ Minerals you say? Why yes, I'll take a dozen or so... |
|
Back to top |
|
|
Gail
Joined: 21 Feb 2008
Posts: 5839
Location: Texas, Lone Star State.
|
Posted: Apr 16, 2008 15:00 Post subject: Re: Gail's collection |
|
|
This isn't the most expensive topaz we have, but it is the one that has the most appeal to me. At least when we are talking Imperial topaz.
This is a gorgeous reddish orange imperial triplet with three nearly parallel elongated gemmy and transparent highly refractive xls, with "very rare doubly terminated cyrstals". Each termination is an attractive modified pyramidal point, with distinct pyramidal faces on all three cyrstals at the base, as well.
Okay, so I am a sucker for these!
You have got to love nature!
Description: |
Topaz ( triple "imperial" ) Ouro Prieto, Minas Gerais, Brazil 6.1 x 1.7 x 1.4 cm |
|
Viewed: |
43900 Time(s) |
|
_________________ Minerals you say? Why yes, I'll take a dozen or so... |
|
Back to top |
|
|
Pete Modreski
Site Admin
Joined: 30 Jul 2007
Posts: 709
Location: Denver, Colorado
|
Posted: Apr 16, 2008 15:11 Post subject: Re: Gail's collection |
|
|
Thanks for continuing to post your pictures, Gail. Love the aquamarine, kunzite, and topaz!
Pete
|
|
Back to top |
|
|
Gail
Joined: 21 Feb 2008
Posts: 5839
Location: Texas, Lone Star State.
|
Posted: Apr 16, 2008 15:18 Post subject: Re: Gail's collection |
|
|
Thank you Peter!
I had a little spare time to post and thought what better way to spend time than doing so. I don't much like television and prefer to listen to good music and share my minerals with this group. It has really given me a re-education in that I have to type all the info out and it forces me to pay attention to details.
Besides, I would just be mowing if it weren't for promising to add more minerals on here and what could be wrong with that picture?! ha!
Again, thank you.
Gail
_________________ Minerals you say? Why yes, I'll take a dozen or so... |
|
Back to top |
|
|
GneissWare
Joined: 07 Mar 2008
Posts: 1287
Location: California
|
Posted: Apr 16, 2008 15:24 Post subject: Re: Gail's collection |
|
|
Hi Gail,
That outstanding Malachite really doesn't fit well into the rest of your collection. I would be willing to take it off your hands! Ha! Of course, that applies to most of the other rocks you've posted. I can send you my shipping address.
Bob
|
|
Back to top |
|
|
Gail
Joined: 21 Feb 2008
Posts: 5839
Location: Texas, Lone Star State.
|
Posted: Apr 16, 2008 15:27 Post subject: Re: Gail's collection |
|
|
Well Bob, if you are willing to fight off the others that have it on their list of "must haves' then I say go for it!
How about the next best thing, come visit it? Dallas isn't that far away surely?
You might even get a glass of wine to go along with your viewing pleasure!
_________________ Minerals you say? Why yes, I'll take a dozen or so... |
|
Back to top |
|
|
|