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Post by rockjunquie on Jul 7, 2024 18:49:10 GMT -5
Chrysocolla hardness can be all over the place... Gem Silica is still all around called Chrysocolla... whether it is a misnomer or not (and maybe should be called more properly Chrysocolla Chalcedony), it's as hard as any Turquoise. I've had some super hard chrysocolla. I have one piece that I gave up grinding on. One day, I may go back to it. It's really beautiful. There is a chrysocolla from Peru that is really hard, too.
I thought gem silica was chalcedony stained with chrysocolla (copper?). I know I'm not using the correct term. It's really hard.
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RWA3006
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Post by RWA3006 on Jul 7, 2024 19:19:04 GMT -5
RWA3006 - Thanks you for that information. I don't know if this specimen of coprolite was worth cutting open, but the collector thought it worth opening. I can't tell the good ones from the bad ones at this stage. I have more in the collection, like this one below. It might be asking a lot, but could you tell me what to look for as far as spotting which ones are good vs bad quality? ![](https://res.cloudinary.com/dosm6sdda/image/upload/v1720384835/fvMHqF4WQq6FR-61YztxHw_wuouxt.jpg) Coprolite is a gamble every time because you really can't tell what's inside till you cut it. That being said, I'd never bother cutting one that wasn't obviously agatized like the typical ones we find in Utah. I look for a solid specimen without cracks and hints of agate color peeking through the surface. Maybe it's my imagination but the bright colors and interesting patterns seem to vanish in specimens larger than a cantaloupe, so I usually don't mess with them anymore unless I want a yard ornament. I've found many that are the size of a truck tire that are broken and nothing of interest is inside as far as color and contrast.
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tribeunited
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Post by tribeunited on Jul 7, 2024 19:27:59 GMT -5
Ok all - I will run that test again with copper and post results in a bit. Thanks again :0) RWA3006 - Thank you for coming back to explain that. I am slowly learning, so I appreciate your input. ![:)](//storage.proboards.com/forum/images/smiley/smiley.png) I can't even imagine the size of the dinosaur who left those car sized ones, scary!
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Post by vegasjames on Jul 7, 2024 19:55:04 GMT -5
Chrysocolla hardness can be all over the place... Gem Silica is still all around called Chrysocolla... whether it is a misnomer or not (and maybe should be called more properly Chrysocolla Chalcedony), it's as hard as any Turquoise. What is commonly known as silicated chrysocolla is not chrysocolla. Actual chrysocolla is a very soft mineral of hydrated copper silicate. What is commonly called silicated chrysocolla, which includes gem silica is a much harder chalcedony (quartz) stained by copper salts. Therefore, it is not chrysocolla, which is a different and again much softer mineral.
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Post by vegasjames on Jul 7, 2024 20:01:56 GMT -5
Chrysocolla hardness can be all over the place... Gem Silica is still all around called Chrysocolla... whether it is a misnomer or not (and maybe should be called more properly Chrysocolla Chalcedony), it's as hard as any Turquoise. I've had some super hard chrysocolla. I have one piece that I gave up grinding on. One day, I may go back to it. It's really beautiful. There is a chrysocolla from Peru that is really hard, too.
I thought gem silica was chalcedony stained with chrysocolla (copper?). I know I'm not using the correct term. It's really hard.
Yes, gem silica is a type of chalcedony stained with copper salts, not just chrysocolla. And it differs from chrysocolla in being a form of quartz, which is much harder than true chrysocolla. Actual chrysocolla is quite rare, very soft, and is a hydrated copper silicate. Therefore, gem silica and other forms of what is commonly called "silicated chrysocolla" is not really chrysocolla.
Unfortunately, a lot of copper containing minerals commonly get called "chrysocolla" incorrectly. This includes copper ores and any unidentified copper minerals. I have even seen people refer to malachite and turquoise as "chrysocolla".
Again, actual chrysocolla is rather rare. Yet, with as often as we stones being called chrysocolla, it should be so common that we should be tripping all over it when we are out collecting rocks.
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ThomasT
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Post by ThomasT on Jul 7, 2024 20:30:56 GMT -5
At $50-$100 per gram that true Gem grade Silicanized Chrysocolla adds up pretty quick... jewelers have customers standing by.
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tribeunited
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Post by tribeunited on Jul 7, 2024 20:46:40 GMT -5
vegasjames,, ThomasT Maybe one of you knows this, since it seems you do. How does one go about figuring out "gem grade" I've got a bucket of rough chrysoprase, varying sizes and colors. Is there a test to figure out if this is gem grade? What about colors? Are there preffered colors? ![](https://res.cloudinary.com/dosm6sdda/image/upload/v1720403179/8cUVq2HeSbWegskAlV56ww_1_trybx2.jpg)
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Post by rockjunquie on Jul 7, 2024 21:43:14 GMT -5
vegasjames ,, ThomasT Maybe one of you knows this, since it seems you do. How does one go about figuring out "gem grade" I've got a bucket of rough chrysoprase, varying sizes and colors. Is there a test to figure out if this is gem grade? What about colors? Are there preffered colors? ![](https://res.cloudinary.com/dosm6sdda/image/upload/v1720403179/8cUVq2HeSbWegskAlV56ww_1_trybx2.jpg) Those colors are gemmy. That blue one looks like real gemmy gem silica. $$$
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ThomasT
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Post by ThomasT on Jul 8, 2024 6:02:01 GMT -5
Well, I'm not a gemologist but in the images of your rough it appears there may possibly be some portions that could be gem grade material.
As the stones sit, they have not been cobbed for selling as gem grade rough.
What is displayed appears to me to be mostly useful as cabochon grade material.
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tribeunited
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Post by tribeunited on Jul 9, 2024 14:00:04 GMT -5
Thank you for the info rockjunquie - So I take it bluer is better. ThomasT - thank you as well. I'll probably put them aside for now so I don't mess anything good up.
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Post by rockjunquie on Jul 9, 2024 14:59:46 GMT -5
Thank you for the info rockjunquie - So I take it bluer is better. ThomasT - thank you as well. I'll probably put them aside for now so I don't mess anything good up. Send it this way and I'll let you know how it looks in person. ![:)](//storage.proboards.com/forum/images/smiley/smiley.png) Seriously, it should be VERY translucent. It can't be so dark blue that it doesn't "glow".
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tribeunited
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Post by tribeunited on Jul 9, 2024 15:11:07 GMT -5
it's very translucent. I thought it was a plastic at first when I saw it, until I picked it up.
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Post by rockjunquie on Jul 9, 2024 15:12:21 GMT -5
it's very translucent. I thought it was a plastic at first when I saw it, until I picked it up. I bet it's gorgeous in person!
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tribeunited
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Post by tribeunited on Jul 9, 2024 15:16:50 GMT -5
It's pretty cool, not gonna lie. ![:)](//storage.proboards.com/forum/images/smiley/smiley.png) It's like a Caribbean queen. ![:)](//storage.proboards.com/forum/images/smiley/smiley.png)
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