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GeneralPhosphophyllite specimen?

16th Jun 2019 18:14 UTCDeborah Kirkpatrick

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I am a short time member but a long time lurker here on Mindat. My interests are more gemological, but I use this this site to inform myself of what rough can look like in it's various forms.


I have a piece of phosphophyllite that weighs approximately 42 carats. I do not know whether or not this crystal is in good enough shape to be considered a specimen and would appreciate you guy's opinion on this. Although it isn't apparent in any photo I have taken, it is a facet grade stone with few inclusions and could probably yield a stone around 20 carats.


I may have located someone who is brave enough to facet it, but before even discussing it further I would like mineral collectors opinions on this. The crystal's edges are slightly bruised and the back of it where it came off the matrix is broken up.


What do you think?


Debbie K

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17th Jun 2019 04:09 UTCIan Nicastro

That is a very nice specimen, I personally would not cut that up for facet rough even with the chipping and matrix contacts... it's still a great crystal, and has less damage than many specimens I've seen in collections of my friends. Also the finished stone would likely have notable fractures, etc... Specimens of this species, from this mine, are very hard to get ahold of, because the mine has not produced these for awhile.

17th Jun 2019 08:35 UTCKeith Compton Manager

I'd keep it as is too, but then I'm not really into faceted material.


As you said "I may have located someone who is brave enough to facet it" - it may not be that easy to facet the material - afterall it is a relatively unusual mineral to have faceted.


Cheers

17th Jun 2019 14:31 UTCKyle Bayliff

Phosphophyllite is also fairly soft, brittle, and cleaves easily, too. If you do have it cut, your lapidarist needs to be much more skillful and careful than they are brave or you may wind up with nothing but a pile of fragments.

17th Jun 2019 15:26 UTCKevin Hean

Hi Deborah,

Check that stone very carefully for stress , if there are any signs , don't touch a lap, it will pop. another thing the lap should not be coarser than

one or two thousand grit even for roughing,

If that was just a lump of rough I would try to cut it, but you have a fairly decent crystal and according to Ian not so plentiful,

Good luck with the temptation.

17th Jun 2019 16:38 UTCDeborah Kirkpatrick

Thanks for your replies. I am trying to make a determination about whether or not it would be worth more as a specimen or faceted. I am not a mineral collector; I just lucked in to getting this crystal. I know they're valuable as specimens and that they're rarely faceted because of the cleavage issues and softness. As I said earlier, it really is facet grade with only a few inclusions. What you are seeing in the second photo that looks like feathers and inclusions is the back of the crystal which is where it was in contact with the matrix. It doesn't have the great twinning that some of these specimens exhibit, and it does have flea bites on some of the edges. But what a gorgeous glow! It changes color from a pale blue to this great greenish-blue with different backgrounds and of course, different lighting.


Again, thanks. I think I'll contact some mineral dealers and see what they think it's worth. I do have a good idea about what these things go for faceted and this one would yield a really hefty stone. It's one of those "bird in the hand" vs "2 birds in the bush" dilemmas.

18th Jun 2019 00:26 UTCDeborah Kirkpatrick

Thanks to all for your input. I just wasn't sure that this was a good enough example to be considered a specimen.


It honestly is good enough to facet; only one easy to avoid feather and a few minor inclusions. Couldn't get a good picture showing it's clarity.


Thanks again.

18th Jun 2019 01:31 UTCPavel Kartashov Manager

As for me personally, I would break the arms and legs of the brave guy who would agree to cut this stone. >:-(


https://www.youtube.com/watch?v=ax58QPbcx-0

18th Jun 2019 22:35 UTCIan Nicastro

Deborah, a piece doesn't have to be pristine to be considered a specimen. Basically anything can be considered a specimen. But I think what you mean is a 'Fine Mineral' specimen, where the overall aesthetics is the key factor, and damage is often frowned upon... but for some rare species, and pieces from rare locations... some degree of damage is easily overlooked because of the rarity. Also some fine mineral specimens have undergone repair work or stabilization and as long as it is disclosed that is considered acceptable.

18th Jun 2019 23:06 UTCWayne Corwin

Deborah

Try taking an outside photo of it at either early dawn or early dusk, no sun in the sky.

It often works on those hard to photo crystals.


Then show us please.

18th Jun 2019 23:38 UTCDeborah Kirkpatrick

Ian and all who have responded: Is this crystal good enough to be considered a "Fine Mineral" specimen? I do understand that the species is rare and the location has been closed for many years and nothing found subsequently has this color.


Wayne: Don't have my cellphone right now, but when I get it back (hopefully tomorrow) will try to get a picture as you recommend and will post it.


Thanks again, all!

19th Jun 2019 01:55 UTCKeith Wood

I think it is rare enough to be considered a fine specimen. I see dealers with them very infrequently, and lesser pieces have fetched high prices. I have no idea of the potential, as-yet-to-be-realized value of a gemstone, but I think you would find a buyer for it as a specimen. It is a highly sought mineral and a nice example.


I think you are asking for a value comparison between its specimen value and what a gemstone could realize. It will be hard to get that here because most of us lean toward preserving such things. You will often see comments to the effect the gem rough is something that, to us, has essentially no specimen value and so we will grant that it might as well be cut into something valuable.


On the other hand, if you take it to gemstone folks, they will give you a value based on its gem potential. Those heartless schmucks have no problem whatsoever carving up natural works of art and making them into baubles.


I think you see where I'm going.

19th Jun 2019 02:38 UTCSteven Kuitems Expert

Deborah,

I would definitely leave it as is and as a gemmy fine colored specimen it has lots of collector interest!! Why destroy superb natural specimen by cutting??

That is my humble opinion.

Steven

19th Jun 2019 02:53 UTCDoug Daniels

For what it's worth, from a nobody - I agree with the rest. Phosphopyllite is a rare enough species as is - and to have a sample of fair size, with great color, good clarity (enough to make it gem-), and showing even some crystal faces... that is a great specimen. Granted it isn't the something like 3-foot long crystal that made the display rounds in the late 70's... I too would leave it as is - it's more valuable that way, in my opinion as a collector. You are fortunate to have it.

19th Jun 2019 04:57 UTCDeborah Kirkpatrick

Thanks to all of you, you've answered my question. I know that if this were a piece of quartz with this kind of damage it wouldn't be worth anything near what a pristine one would be. I was thinking that perhaps it's rarity would make folks willing to overlook it's imperfections, but wasn't sure. I have a good idea of how much faceted phosphophyllite brings (for those who are curious, about $2,500 a carat) BUT if the crystal itself is acceptable then I'm much more inclined to do nothing. The cleavage issues are horrendous and one could end up with a lot of little pieces. The guy who expressed an interest is well known and respected and would probably have a buyer for such a cut stone.


I like it a lot myself just the way it is, it has a beautiful glow and changes color in different lighting and with different backgrounds. It can go from pale blue to greenish-blue to blueish-green just rotating it around. Strange stone.


Thanks again to all of you. I do feel lucky to have it.

19th Jun 2019 06:23 UTCDale Foster Expert

Pavel Kartashov Wrote:

-------------------------------------------------------

As for me personally, I would break the arms and legs of the brave guy who would agree to cut this stone.
:-(



I feel the same should be applied to whoever broke it out of its matrix.

19th Jun 2019 09:19 UTCAlfredo Petrov Manager

Probably nobody broke it out of its matrix, Dale. A stick of dynamite did the job, and then the zinc miners in Potosi found the loose crystal in the rubble on the floor after the blast. That's how most of the few being found nowadays come to light, and why there is almost always some damage. Blast rubble is not a kind environment ;((

19th Jun 2019 10:08 UTCDale Foster Expert

Fair enough if that is how it was found.


I have to say I am not keen on detached crystals (with certain exceptions), I find it far more interesting to see the mineral in some context with its host rock.
 
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