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Post by liveoak on Dec 30, 2022 10:59:02 GMT -5
I'm looking for input on a Chrysocolla cab.
Not sure if the crazing - which looks like old porcelain (or a crackle glaze on pottery) is just the nature of the stone
OR something I've done horribly wrong (likely)
I won't lie, I kind of like it - it's an interesting effect. Not sure how I'd repeat it.
Anyway, any input appreciated.
Thanks,
Patty |
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Post by 1dave on Dec 30, 2022 12:34:11 GMT -5
Intriguing! Especially if it is repeatable!
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gemfeller
Cave Dweller 
Member since June 2011
Posts: 4,060 
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Post by gemfeller on Dec 30, 2022 16:30:42 GMT -5
I'd have to see it in hand but judging from the images the "crackle" appears to me to be a natural formation in the stone. I like it too -- it adds a lot of extra character and uniqueness to the cab.
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Post by hummingbirdstones2 on Dec 30, 2022 18:33:08 GMT -5
I'll second the opinion that it's a natural part of the stone as it formed.
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Post by hummingbirdstones on Dec 30, 2022 18:36:00 GMT -5
I agree with the 2 gentlemen above.  Very cool stone, Patty! |
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Post by liveoak on Dec 30, 2022 18:46:49 GMT -5
Thank you all, Nice to know that it's not something I did wrong ,
but maybe something that just is, and a nice effect too.
Should make a nice piece of jewelry, thanks for weighing in.
Patty |
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Post by hummingbirdstones on Dec 30, 2022 19:16:35 GMT -5
Thank you all, Nice to know that it's not something I did wrong ,
but maybe something that just is, and a nice effect too.
Should make a nice piece of jewelry, thanks for weighing in.
Patty Looking forward to seeing what you do with it!  |
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Post by vegasjames on Dec 30, 2022 20:18:41 GMT -5
The main stone is technically copper ore, as it contains a variety of copper minerals. Chrysocolla is a specific mineral, hydrated copper silicate. It is extremely soft and cannot be worked easily without stabilization. There are many copper minerals and some can be very hard to ID without testing. Therefore, "chrysocolla" often gets loosely used as a term for any unidentified copper minerals, but this leads to a lot of confusion. I have seen malachite referred to as "chrysocolla" because of this.
The reddish brown of your stone is limonite, which is a mix of iron oxides and hydroxides. Very common in copper mines. The "crackling" is not really crackling. If you enlarge the picture you will see a lot of orbicular structures, not cracks. The limonite filled in and around the voids in the stone.
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Post by liveoak on Dec 31, 2022 7:16:29 GMT -5
The main stone is technically copper ore, as it contains a variety of copper minerals. Chrysocolla is a specific mineral, hydrated copper silicate. It is extremely soft and cannot be worked easily without stabilization. There are many copper minerals and some can be very hard to ID without testing. Therefore, "chrysocolla" often gets loosely used as a term for any unidentified copper minerals, but this leads to a lot of confusion. I have seen malachite referred to as "chrysocolla" because of this. The reddish brown of your stone is limonite, which is a mix of iron oxides and hydroxides. Very common in copper mines. The "crackling" is not really crackling. If you enlarge the picture you will see a lot of orbicular structures, not cracks. The limonite filled in and around the voids in the stone. Thank you - yes they are indeed orbicular.
The best part is that I have a bunch of rough I purchased a number of years ago from a guy mining it in Mexico. Now that the weather is warmer I might just have to get out on the saw.
Thank you for the explanation, Patty
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Post by pebblesky on Dec 31, 2022 12:57:51 GMT -5
I love how it looks.
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Post by Starguy on Dec 31, 2022 20:22:18 GMT -5
It’s a beautiful cab Patty. I think you may be looking at an orange-peel finish. It’s common in some rocks. You might be able to smooth it out but it adds something to the stone somehow. Thanks for showing.
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Post by liveoak on Jan 1, 2023 7:21:27 GMT -5
If it was orange-peel Starguy wouldn't I feel it on the surface ? The cab is perfectly smooth & shiny . Personally I think the orbicular patterns I see seems right to be limonite. I found yesterday that I have another slab cut from the exact rock, so I think I'll try to cab it this week & see if it's repeatable. It would seem if it's repeatable exactly, then it can't be a surface defect, but an inclusion.
What ever it is, I think it's very attractive, and I'm hoping it's repeatable.
Stay tuned.
Thanks,
Patty
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Post by rockjunquie on Jan 1, 2023 7:26:18 GMT -5
If it was orange-peel Starguy wouldn't I feel it on the surface ? The cab is perfectly smooth & shiny . Personally I think the orbicular patterns I see seems right to be limonite. I found yesterday that I have another slab cut from the exact rock, so I think I'll try to cab it this week & see if it's repeatable. It would seem if it's repeatable exactly, then it can't be a surface defect, but an inclusion.
What ever it is, I think it's very attractive, and I'm hoping it's repeatable.
Stay tuned.
Thanks,
Patty
I agree. It doesn't look like orange peel. I have seen some materials with that pattern. Copper materials. I've seen shattuckite, azurite and malachite with that bubbly appearance. Prolly more, too.
At first, I thought that was Sonoran chrysocolla with cuprite, but James knows his copper ores.  |
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Post by 1dave on Jan 1, 2023 15:06:22 GMT -5
 I think they are brand new baby quartz crystals. |
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Post by liveoak on Jan 2, 2023 11:05:53 GMT -5
So now you have me wondering further.
Now I believe vegasjames is correct that the reddish brown of the lower slabs & my cab are limonite. When I looked up limonite the photos & descriptions of the round formations tie in perfectly.
OK, but what about the top slab- which I was told was Sonoran chrysocolla with cuprite.
How in the world can you ID the 2 different reddish brown sections ?
Cuprite vs limonite
I see what you mean James about the copper minerals and how they all get grouped together as "Chrysocolla",
but how can you tell what's what ?
Putting the slabs next to each other obviously the top one is darker - but that could mean just a better grade ?
Any tips, I'd appreciate the help.
Thank you,
Patty
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Post by 1dave on Jan 2, 2023 12:01:36 GMT -5
At some geological point the copper atoms appeared in whatever form.
In clay or sand or limestone surroundings. Then naturally . . .
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Post by rockjunquie on Jan 2, 2023 12:09:18 GMT -5
So now you have me wondering further.
Now I believe vegasjames is correct that the reddish brown of the lower slabs & my cab are limonite. When I looked up limonite the photos & descriptions of the round formations tie in perfectly.
OK, but what about the top slab- which I was told was Sonoran chrysocolla with cuprite.
How in the world can you ID the 2 different reddish brown sections ?
Cuprite vs limonite
I see what you mean James about the copper minerals and how they all get grouped together as "Chrysocolla",
but how can you tell what's what ?
Putting the slabs next to each other obviously the top one is darker - but that could mean just a better grade ?
Any tips, I'd appreciate the help.
Thank you,
Patty
I used to bug vegasjames about these things, too. I even wrote down a cheat sheet (somewhere around here). I feel fairly confident about it now. I'll let him answer, though. |
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wpotterw
spending too much on rocks
Member since September 2016
Posts: 446
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Post by wpotterw on Jan 2, 2023 13:27:22 GMT -5
So now you have me wondering further.
Now I believe vegasjames is correct that the reddish brown of the lower slabs & my cab are limonite. When I looked up limonite the photos & descriptions of the round formations tie in perfectly.
OK, but what about the top slab- which I was told was Sonoran chrysocolla with cuprite.
How in the world can you ID the 2 different reddish brown sections ?
Cuprite vs limonite
I see what you mean James about the copper minerals and how they all get grouped together as "Chrysocolla",
but how can you tell what's what ?
Putting the slabs next to each other obviously the top one is darker - but that could mean just a better grade ?
Any tips, I'd appreciate the help.
Thank you,
Patty
Top slab is Sonoran Sunrise from a 2.25 lb chunk of it. |
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Post by liveoak on Jan 2, 2023 14:16:35 GMT -5
Top slab is Sonoran Sunrise from a 2.25 lb chunk of it. You're right Bill, and in fact it came from YOU (thank you).
So am I wrong to call it Sonoran chrysocolla, meaning that Sonoran Sunrise is different ??
Patty ... realizing how little she knows about rocks more and more every day.
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Post by Son Of Beach on Jan 2, 2023 14:50:49 GMT -5
Top slab is Sonoran Sunrise from a 2.25 lb chunk of it. You're right Bill, and in fact it came from YOU (thank you).
So am I wrong to call it Sonoran chrysocolla, meaning that Sonoran Sunrise is different ??
Patty ... realizing how little she knows about rocks more and more every day.
Welcome to the club lol  |
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