FMF - Friends of Minerals Forum, discussion and message board

[Aymeric]

Greetings everyone !

I got a phone call from a supplier of mine today, the man was very excited telling me a miner had brought him a specimen of peridot on lapis.
"uh ? Waaaa? can you repeat please ??"
He confirmed and assured me that it was indeed some peridot on lapis. I've never heard about and even less seen anything like that, and I'm a bit doubtfull actually as the man sometimes make crazy identifications.

What are our local expert thinking about this ? Is it mineralogically possible that péridot & lapis form together ? I don't know wether by lapis he meant massive lapis lazuli or lazurite crystals. I'm waiting for some photos of it and will share them when I receive the email.

Cheers !

[Pete Modreski]

As others will probably reply also, I cannot imagine that they would occur together (and certainly not in gem quality of either one or both).

I'm sure we are all thinking that there are all sorts of possibilities for people to "manufacture" specimens of the two together.

Pete

[Peter]

I agree with Peter M as no surprise. I have had one lovely specimen from Sar-e Sang I got some 20 years ago in which there were also garnets, pyrite and some several centimeter large green gemmy crystals of possibly Nepheline. I let a friend have that piece but did not hear of analyses. I have a photo but not easily available.
This could be the same. Color is more light green with a yellow tone, semi gemmy, elongated. And I would not be surprised to see new minerals from this interesting deposit.

[Peter]

Here is a snapshot of the combo!

[lluis]

Good morning

Could not be that the grenish crystals are just the fluoro-potassirichterite, that was also sometimes identified as winchite?

https://www.mindat.org/min-7244.html
https://www.mindat.org/photo-185604.html

The not so gemmy that I saw two years ago looked like the crystals that are near the lazurite crystal.....

With best wishes

Lluís

[Aymeric]

Greetings everyone and thanks for replies.

I had my sup. on the phone a short a while ago and asked him more about this piece, he told me that the peridot is on massive lapis, not with lazurite.
The piece have been shown to several people there and some have supposed it was diopside. He told me one of them is a geologist who said that although uncommon, this happen sometimes. I'm still waiting to get a picture, but the specimen is still in miner's hands, so I don't know when I can get one.

Lluis, I have some richterite.winchite specimens, and I jardly see how it could be confused with some péridot. I don't think it's this mineral species.

Well, I suppoe we'll have to wait for the picture, I'll keep you informed when I get it !

[Claus]

If it is an amphibole, it should be easy to see the cleavage planes.
Nepheline is hexagonal, has no cleavage and a grain will gelatinise in muriatic acid.

All the best

Claus

[ikram]

Aymeric.
didn't see any Peridot with Lapis from the locality ,
i suppose to be green Daiopside or Nepheline from Badakhshan.

Ikram.

[Aymeric]

Greetings everyone !

I've received a picture of the thing. Well, it's not on massive lapis, but along with some Lazurite as you can see. The color is indeed reminding of peridot. What do you people think of it ?

[Pete Modreski]

Thanks, Aymeric, for following this up with the picture.

The color certainly looks like much peridot that one sees, though, it could well be diopside too. I had been tempted to write back earlier to say that, it is "possible" that lazurite and forsterite, certainly could, in theory, occur together, as could lazurite and diopside. I just thought I'd wait until "more information was forthcoming".

I've just searched on Mindat for the associations of lazurite + forsterite, and lazurite + diopside. It yields 3 localities for the first pair, and 13 localities for the second. One for the latter (with diopside) association is the Sar-e-Sang district, Koksha Valley, Badakhshan, Afghanistan, the reference for which is a 2002 Journal of Petrology article.

Pete

[Craig Mercer]

Hi Aymeric,

I also agree with Pete. Could be Peridot/Lazurite, but Diopside/Lazurite would be more likely. Either way the contrast in colours is spectacular.

Goodluck my friend
Craig.

[Jordi Fabre]

Usually the Diopside from Pakistan is fluorescent but the Forsterite not. Why you or your colleague don't try the fluorescence?

BTW, welcome to FMF Craig, is nice have you here.

[Craig Mercer]

Thank you Jordi for the warm welcome. A lot of very interesting reading within the discussions on your forum. Thanks also for making it available for all to be a part of.

Kind regards
Craig.

[Aymeric]

Greetings everyone, thanks for the replies


I was pretty misled by supplier who told me that the crystal was on massive lapis, which is not.
I actually have quite a number of Lazurite specimen which are also bearing other crystals and was always wondering about their identity.
They seemingly have same cristalization, but they range from a gemmy yellow green, to opaque creamy green, to minty green. Among them is a piece which along the lazurite crystals bears some beige colored ones. One of them is broken, and one can see that the inner part is gemmy, while the outer is geinge and dull. Maybe some pseudomorph ?
I'll try to find some time to take pics of all the different kind of crystals I can find on the different pieces I have.
Sorry if my replies come late, I'm quite busy with work and just don't have the time to connect & post everyday.

Jordi,I had never heard about Pakistani diopside being fluorescent. is it so under short wave UVs ? well, as a matter of fact, my supposedly alchuri diopside are not fluorescent at all.
My supplier alas have no uv lamp at hand...

Hey Craig ! Glad to see you and your eye-popping collection around !

have a great monday everyone !

Aymeric

[Jordi Fabre]

Short UV