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What defines a mineral's 'quality?' - (13)
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Tracy




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PostPosted: Mar 22, 2008 10:18    Post subject: Re: What defines a mineral's 'quality?' - (13)  

Pete - not meaning to be a trouble-maker here...I have heard it said that black/white mineral specimens are less desirable than colored minerals, but does this speak more to popularity than to quality? These two elements are often hard to tease apart from each other, but I would not regard them as interchangeable...? (in other words, aren't there plenty of high-quality ferberite and schorl and milky quartz specimens out there) With respect to "durability" and clarity, I can see where there might be more overlap, but not with color versus black and white (think photography for example).

Sorry if I missed something here...
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Konstantinos Ch.




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PostPosted: May 14, 2008 09:11    Post subject: Re: What defines a mineral's 'quality?' - (13)  

Hello all!

Wonderful topic! I love it!

This is my opinion :

Quality equals rarity.Not rarity of the mineral species, but rarity of the specimen. Now, what defines rarity of a specimen:

1- Aesthetics- Color, clarity, position of crystals, luster, displayability, form, combination of species, sharpness of crystals, shape of crystals , trim-work , overall appearance. A specimen that exhibits all or most of this characteristics is rarer than a specimen that doesn't, so it's of higher quality.

2- Locality - Some localities are famous because they produce the best representatives of some mineral species. The specimens of that very species from this locality are of higher quality. Some species rarely come out of a specific locality with specimen-grade crystals, so, although they are not the best representatives of the species, the specimens are considered to be of high quality. For example Azurite from Tsumeb is the best and it is considered to be of high quality. However, the Mexican ones are very fine for Mexico and are still considered of good quality. When a specimen of Mexican Azurite is equal to one from Tsumeb considering all the factors except locality, the first specimen is of higher rarity (and so quality...) than the second.

3- Condition -Very important ! Damage and contacts reduce the quality of a specimen. However, a collector has to consider other factors, too , like the delicacy of the species and comparison to similar specimens in existence- for example, as I always say, totally pristine specimens from Madan are VERY RARE, so I tolerate minor damages for my collection. Also, trim-work related to the condition like repairs reduce the quality.

4- Size of crystals- This counts the most for species that rarely come out in big crystals or rarely the larger crystals are aesthetic. For example, Shigaite, The bigger the crystal, the higher the quality.

5- Size of specimen- Since collectors started to specialize their collections at a specific size of specimens (thumbers, miniatures , small cabinets etc. ) we have to consider this factor, too. A Thumbnail of a Topaz should be judged as a thumbnail of a Topaz, not just as Topaz specimen. There may be several specimens of bigger size that are of higher aesthetics, but when at this size a specimen can't get better, then it's rarer.

6- Mineralogical importance- Rare crystal habits, well-defined crystal faces , symmetry in crystal form, crystal twinning, inclusions , skeletal or other special growth , natural etching and polishing, pseudomorphy, fluorescence, dichroism and in general all the mineralogical phenomena that occur rarely are factors that increase the quality, when a specimen exhibits any of them.

7-Mineral species- Of course, when a mineral species is rare, the specimen is rare. However, the grade of rarity of such a specimen depends on the number of similar pieces in existence. If we have a find of 200 similar pieces of a rare mineral and a single specimen of a common mineral with a unique habit for its species, the latter is much rarer specimen, independently the species of the 200 specimens is rarer in general.

8- Time of mining- Some specimens are also used as mineralogical antiques. An otherwise common specimen which has survived 100 years is rare first because it survived, and because it's a the only or one the few representatives of an old find. Those specimen have historical value.
On the other hand, a brand new find of material different than the older ones makes a specimen of this material potentially rare, since the collector can pick his own out of the lot and the find will be old soon.

9-Classic material- Some specimen of a specific find prove to be the best worldwide or from a specific locality. This makes the pieces of the find rarer than similar ones.This factor is actually a combination of other factors.

10-Size of the lot- When a lot of similar specimens comes in a small number of specimens the specimens get rarer.

11-Matrix- Some finds consist mostly of free-standing crystals and some other of matrix pieces. The proportion between matrix and non-matrix specimens at a given material defines the rarity of the two different types of specimens.

Now, the rarity of a specimen is always defined as a combination of all those factors. And here comes in the game the subjectivity John was talking about. A specimen almost never exhibits all those characteristics and it's up to the collector to chose for which of those factors absence to be tolerant. For example, I prefer my crystals to be gemmier and less sharp than sharp and less gemmy, if i have to chose between the two characteristics.

So between the two unique specimens of matrix Ruby of the same find, of the same size, with same sized crystals, both at perfect condition with intensive color and both with twinned crystals but one of them with clear more rounded crystals and the other sharply formed textbook but more opaque crystals, I'll pick the first one. Some other collector would pick the second. Here the rarity is the same and it's a matter of preferences.

Hope i helped!
-Kostas.
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jimB




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PostPosted: Dec 11, 2009 23:49    Post subject: Re: What defines a mineral's 'quality?' - (13)  

I agree with the notion that quality is a rarity factor. I have not heard many people express this so I enjoyed your observation, Konstantinos.
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cascaillou




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PostPosted: Nov 27, 2011 11:38    Post subject: Re: What defines a mineral's 'quality?' - (13)  

I agree that absence of damage is definately important for a quality specimen (and if any repairs have been done, these must be mentionned!).

A quality specimen also needs to be free of any treatments (no oils or resins, no polishing of the crystal facets, no heating, no irradiation...). Which is somewhat problematic as heating and irradiation are not always detectable, even with laboratory analysis.

In my mind, the only acceptable processings are:
-triming of the matrix
-elimination of carbonates/oxides crusts (by the use of acids or dithionite) so to reveal the embeded crystals
-cleaning the crystals from earth, dust and grease (using water, alcohol, acetone, soap)
-mechanical cleaning (as long as it doesn't involve any polishing nor carving)
-ultrasonic cleaning
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basti




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PostPosted: Mar 29, 2012 06:26    Post subject: Re: What defines a mineral's 'quality?' - (13)  

I think that this is far subjective and very difficult to tell. The first and most important thing is WHERE you buy. Generally western Europe, USA, Canada and Australie are several times more expensive then the rest of world. There are thousands of sellers and many overprice items up to X0.000%. This is just speculation and it has nothing to do with real quality.

If we strip speculative part of the price, then of course applies everything mentioned about physical properties, size, aesthetic quality, damage, treatment etc. Still one tricky thing survived - yes, it is locality. There are many people very sentimental about some localities, some are called "classic" and blahblah... If there are two localities, both totally depleted and both producing aprox. same quality specimens, but only one is known as "classic" - wonder which specimens will cost 100x more? But again this has nothing to do with quality.

I prefer to buy high (physical) quality specimens from anywhere but only cheap. This cuts off locality sentiment and speculative part of the price. Good aesthetic and undamaged specimen is easy to swap or sell anytime and during the years, ALL localities become depleted. If you buy some "classic" stuff you pay high premium for that classic label but there might be dozen of sites producing same or better quality 10x cheaper. If you are rich and specialized on some certain site then ok. For most general buyers-collectors I consider buying only classic pieces as quite bad investment.
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Pierre Joubert




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PostPosted: Mar 29, 2012 12:55    Post subject: Re: What defines a mineral's 'quality?' - (13)  

Very interesting contributions! In some respects rocks are like humans, very few are pretty and undamaged, most of us have nicks and dings! But, there are other aspects that can make both valuable. Beauty is in the eye of the beholder!
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Peter




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PostPosted: Mar 30, 2012 07:15    Post subject: Re: What defines a mineral's 'quality?' - (13)  

Thank you for many angles and insights. I also agree fully with the last note.

Many times I have heard collectors complain about a repaired specimen. I think all of us or our spouses, children or parents have some repair, tooth, broken leg, internal operation etc. Do we discard them for that?

Some of the most unusual, beautiful or rarest, finest specimens in the world are repaired.
The great Phosphophyllite, the Rocket rubellite from the Jonas Mine,
even the Akropolis and the Abu Simbel :)

Damage is all down to magnification really, same as in humans. I have some 35 specimens out of thousands in my collection which are repaired. I love them no less than any others and they constiute some of my very best as well.

Many years ago Wayne Thompson let a few dozen mineral museum curators and long term collectors vote for the best minerals on exhibit in the cases of Steve Smale, Bill Larson, Gene Meirean. The evaluation was cleverly done in the way you would put your 1st, 2nd and so on choice in each individual case as well as in all cases combined .

My priorities was entirely in line with the general consensus of those some 50+ evaluations, preferences, except in one case where I put one single crystal on a somewhat higher appreciation. The reason being that this particular specimen is truly exceptional for any locality, but perhaps the finest in the world from a classic rare one. but from this classic locality. I have visited in person and studied during many years, read all there is to read about it starting from the 1700s and on....so the interest and knowledge of a locality and the rarity of that quality from that locality of course influences our appreciation.
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crazy.stone




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PostPosted: Jun 05, 2013 02:49    Post subject: Re: What defines a mineral's 'quality?' - (13)  

Wow, this is a pretty good topic. Actually I am a newer and having the similar questions. I will read again and taste the ideas slowly. Many of the above ideas are very good ones, but I believe as the collections, there are random reasons same as other collections. If one like it, he would like to buy no matter where is explored, rare or not, what color it is.....
But if you have seen as much as minerals you can, you will get a clear judgement for the one you see now. Thanks guys, I am happy to see such different topics here.
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Jordi Fabre
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PostPosted: Jun 05, 2013 04:46    Post subject: Re: What defines a mineral's 'quality?' - (13)  

crazy.stone wrote:
Wow, this is a pretty good topic....

Right. This is the typical case of a very interesting thread a little bit lost. So, that's why we created the Featured Columns of FMF, to save these "lost" interesting topics. So, I numbered, and moved this topic to the Featured Columns of FMF section. For more info about how the Featured Columns of FMF section works, please use this link

Tracy, the author of the first post in this thread and therefore creator of it is already mentioned in the THANK-YOUs in the correspondent reference thread

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Mark Ost




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PostPosted: Jun 05, 2013 17:11    Post subject: Re: What defines a mineral's 'quality?' - (13)  

Pierre Joubert wrote:
Very interesting contributions! In some respects rocks are like humans, very few are pretty and undamaged, most of us have nicks and dings! But, there are other aspects that can make both valuable. Beauty is in the eye of the beholder!

Ah Pierre
You remind me how lucky I am that the gift of perfection, in myself (of course), should not be taken for granted! But fear not there may be further incarnations and the good karma you have piled up may be rewarded!


Note to users: You won't get far in life listening to me!

People, like minerals, grow on their imperfections.
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Mark Ost




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PostPosted: Jun 05, 2013 17:18    Post subject: Re: What defines a mineral's 'quality?' - (13)  

Seriously; I agree with everything said but there is a certain undefinable symmetry or rightness in a beautiful piece, aside from rarity and lack of damage. In Japanese the word is "shibui" which translates into roughly aesthetic good taste. A kimono with a small chrysanthemum embroidered may be shibui. A karate uniform (gi) with a bunch of patches and club name embroidered is definitely not.
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Mike P.




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PostPosted: Aug 29, 2013 20:20    Post subject: Re: What defines a mineral's 'quality?' - (13)  

A minerals quality can be judged by the same criteria that diamond is analyzed. To look at two diamond that appear the same, but under other specification they are not of same quality.
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valere




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PostPosted: Aug 30, 2013 10:25    Post subject: Re: What defines a mineral's 'quality?' - (13)  

I like a lot this link! Many interesting data from many style of collectors!

The comparaison with humans is a very neat way to explain the various ways to collect!

Charm and "academic" beauty can be two different concepts, seldomly combined. When combined, we have a "11". Some are botox and silicone fans , others are allergic to this! The same in minerals! However, to repair a broken bone makes sense! Beauty can be defined with trends and change with time, charm is timeless! Rarity and/or originality are key concepts to my opinion! One of my favorite specimens is a 53 kg rock. Most would trim it to keep the main crystal vug. I will never do, because the remaining of the specimen illustrates the geology of my favorite deposit and the environement in which the crystals developped. Added to that, if the rock made a long incredible trip, almost miraculous, it is to stay intact!

To be addict of the trends can be dangerous and costly, as trends change with time and are often artificialy manipulated like in fashion or now, mobiles, where the dealers decide what people will want! The architecture illustrates that very well! Art Nouveau for instance! First trendy, then out of trend, some of the best building have been destroyed! That said, some minerals like liroconite are trendy for centuries...

The most beautiful collections are not the one that combine calibrated specimens of the most trendy minerals, but the ones that have a signature, the fingerprint of the collector who built it! Collections where we can see a purpose, or where we can feel the eye and spirit of the collector, just like a painting.That can't be compared or similar to any other! Full of unpredicatable things that can't be seen anywhere else! A mineral collection is like a work of art. All the specimens that contribute significantly to that work, to that signature, is a quality specimen. The others can easily move away. This means that in one collection, a specimen can be essential and have important qualities, while in another collection,the same specimen might have little significance! That goes from tiny systematic specimens up to masterpieces of any size, that can share the same room. Other collections illustrate the love and obstination of some collectors for some mines where they selfcollected.

The best private collections (to my taste, "best" means a personal opinion) I have seen so far have a strong fingerprint, with specimens sublimating each other! Bringing admiration and a lot of learning! The favorite private collection I have seen so far combines all the above!!

Cheers!

Valère, Belgium
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Pierre Joubert




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PostPosted: Jan 01, 2014 03:58    Post subject: Re: What defines a mineral's 'quality?' - (13)  

This topic is, to me, one of the most interesting topics on this forum and one that can be endlessly discussed. The contributions by John, Jordi and others are very useful indeed. Sometimes we part with a specimen only to learn later on that that was a once off specimen. OUCH!!! There are a few such specimens that I wish we still had! Because every mineral has it's own unique identity, some are just irreplaceable!

When searching for a really good specimen from an area, it is wise to consult an expert from the spesific area before parting with your hard earned money. Trust is more worthy than gold, and an expert can guide you to the best as he/she knows what a good specimen from that area looks like.

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cascaillou




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PostPosted: Jan 18, 2014 10:02    Post subject: Re: What defines a mineral's 'quality?' - (13)  

Agreed, it is essential to learn about what you're planning to acquire, and see as much specimens as possible, so you will be able to recognize instantly the few specimens that have "something more" compared to other specimens of the same species and same locality.

A criteria that wasn't mentionned here but that I can be sensitive to is the didactic potential of a given specimen, i.e. a specimen that illustrates some interesting point of mineralogy is a specimen which actually tells something about this science, and that can be discussed.
For instance, I recently saw a quartz specimen with radioactive inclusions, and smoky radiation halos around these inclusions (contrasting with the otherwise colorless quartz): I find it interesting that this specimen is an opening on a scientific discussion about both radioactivity and causes of color (color center in this case), so that this specimen also had some real pedagogical potential (you could actually write a few pages about this single specimen!). Indeed there's something more interesting to discuss about this specimen than just its formal beauty or rarity. Which is incidentally excellent if you're willing to share your passion with other people.
In the same way, other specimens might properly illustrate some interesting points of crystallography, optical phenomenoms, crystallogenesis, etc...
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cascaillou




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PostPosted: Jan 18, 2014 12:00    Post subject: Re: What defines a mineral's 'quality?' - (13)  

as it comes to aesthetics, I appreciate well balanced and contrasted associations
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