|
|
Post by toiv0 on Mar 9, 2020 9:43:15 GMT -5
Came across a container what I a am thinking is blue Peruvian opal. Light for its size, Conchoidal Fractures and is shine.    |
|
|
|
Post by knave on Mar 9, 2020 9:49:45 GMT -5
That is beautiful.
|
|
|
|
Post by fernwood on Mar 9, 2020 13:50:50 GMT -5
Nice container to find.
|
|
|
|
Post by hummingbirdstones on Mar 9, 2020 21:41:27 GMT -5
Looks like Peruvian blue to me, Billy. I have a stash put away that I bought years ago and haven't cut. Worth some do-re-mi now. You can't find clean Peruvian blue to save your soul nowadays.
You got a pretty good size stash there! 
ETA: It's sold by the carat now, btw.
|
|
|
|
Post by toiv0 on Mar 10, 2020 1:49:20 GMT -5
Looks like Peruvian blue to me, Billy. I have a stash put away that I bought years ago and haven't cut. Worth some do-re-mi now. You can't find clean Peruvian blue to save your soul nowadays.
You got a pretty good size stash there!
ETA: It's sold by the carat now, btw.
Then I probably shouldn't give it a way? |
|
|
|
Post by hummingbirdstones on Mar 10, 2020 7:57:57 GMT -5
Looks like Peruvian blue to me, Billy. I have a stash put away that I bought years ago and haven't cut. Worth some do-re-mi now. You can't find clean Peruvian blue to save your soul nowadays.
You got a pretty good size stash there!
ETA: It's sold by the carat now, btw.
Then I probably shouldn't give it a way? Not unless you want to give it to me.  |
|
|
|
Post by MsAli on Mar 10, 2020 14:15:58 GMT -5
Then I probably shouldn't give it a way? Not unless you want to give it to me.   |
|
|
|
Post by knave on Mar 10, 2020 14:29:28 GMT -5
Billy I’d take a 200 carat free sample parcel also.  |
|
reynedrop
starting to spend too much on rocks
Member since February 2020
Posts: 204 
|
Post by reynedrop on Mar 10, 2020 20:18:36 GMT -5
|
|
|
|
Post by rmf on Mar 10, 2020 21:11:10 GMT -5
Based on the Color I would say Gem silica (Chryscolla)
|
|
|
|
Post by hummingbirdstones on Mar 10, 2020 21:31:55 GMT -5
Based on the Color I would say Gem silica (Chryscolla) Ack! I didn't even think of gem silica it being so rare to see nowadays.
@tiov0, you need to find out for sure which it is. It's a lot of money either way, but if it's gem silica, it's way more expensive. The second picture with the single piece looks more like Peruvian Blue to me, but there are some pieces in the tub that look more like gem silica.
Opal has a specific gravity of 1.98 - 2.5. Gem silica is 2.58 - 2.64, considerably heavier.
From your description on the weight and the conchoidal fractures, I'm more inclined to think opal but until you get a specific gravity reading on it, I can't say for sure.
|
|
|
|
Post by hummingbirdstones2 on Mar 10, 2020 21:46:25 GMT -5
Looks like one piece of Chrysocolla in that first handful.
If it isn't opal like you were hoping for I'LL take it off your hands. Just so you aren't disappointed every time you see it, of course... .
|
|
reynedrop
starting to spend too much on rocks
Member since February 2020
Posts: 204
|
Post by reynedrop on Mar 10, 2020 22:34:58 GMT -5
Looks like one piece of Chrysocolla in that first handful.
If it isn't opal like you were hoping for I'LL take it off your hands. Just so you aren't disappointed every time you see it, of course... .
I was thinking about chrysocolla too honestly, but that up close one threw me off (it has a quality that doesn't look like my chrysocolla and that I don't know the word for, maybe resinous). As I had never seen peruvian blue opal, I didn't want to assume. That said... some blue opal gets its color from chrysocolla inclusions: "The copper content in blue opal is up to 1% Cu, it is coloured by irregular microscopic inclusions of chrysocolla (Fritsch et al., 1999) or other Cu silicate. Galillou et al. (2008) states that the inclusions can be Mg-rich shattuckite." (gemdat). So idk? I don't know what to make of that information. |
|
gemfeller
Cave Dweller 
Member since June 2011
Posts: 4,039 
|
Post by gemfeller on Mar 11, 2020 0:29:15 GMT -5
It just doesn't quite look like Peruvian blue opal to me. It lacks the translucence and the fracture seems a little off to me. Opal fractures are generally much shinier and not so blocky. I think Robin is on the right track: density. If you have a known piece of common opal, simple heft should give you a general comparison.
If it's heavier/denser than opal that still doesn't ID it for sure. I'd guess it's definitely a copper family mineral but they are manifold. It doesn't have the luster I associate with gem silica but you can't tell too much from an image. Whatever it is it should be great cutting material. My guess that this point would be chrysocolla.
|
|
reynedrop
starting to spend too much on rocks
Member since February 2020
Posts: 204
|
Post by reynedrop on Mar 11, 2020 1:17:03 GMT -5
It just doesn't quite look like Peruvian blue opal to me. It lacks the translucence and the fracture seems a little off to me. Opal fractures are generally much shinier and not so blocky. I think Robin is on the right track: density. If you have a known piece of common opal, simple heft should give you a general comparison. If it's heavier/denser than opal that still doesn't ID it for sure. I'd guess it's definitely a copper family mineral but they are manifold. It doesn't have the luster I associate with gem silica but you can't tell too much from an image. Whatever it is it should be great cutting material. My guess that this point would be chrysocolla. I would agree that I would say this looks opaque. The second pic is kind of what confused me because it isn’t totally opaque. But also not what I would describe as translucent. Would testing hardness be helpful here? My understanding is gem silica = chrysocolla in chalcedony. Chrysocolla itself has a really low Mohs, like 2.5-3, right? It’s only when it’s in chalcedony that it’s harder, like 6.5-7. And then I think regular opal is like 5.5-6.5. If quartz scratches it readily, and it scratches fluorite or obsidian, wouldn’t that support opal? If fluorite/obsidian scratch, plain Chrysocolla. But if quartz or chalcedonies like jasper don’t scratch it (discernibly), gem silica. |
|
|
|
Post by toiv0 on Mar 11, 2020 20:25:19 GMT -5
I don't think its heavy enough to be gem silica. I will play around with it when I get back.
|
|
|
|
Post by fernwood on Mar 12, 2020 7:30:55 GMT -5
It does have the appearance of some of the chrysocola I have. You saw those when you were here. Am interested in what it really is.
Add me to this list who would like some, for pay, of course.
|
|
