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Identity HelpThis was sold as Diopside, but I think it is Tremolite, am I right ?

8th Sep 2016 12:50 UTCAymeric Longi

Greetings everyone! :)

I've bought a while ago in Peshawar a large crystal (roughly 15cm x 10cm) of what I was told to be diopside from Badakhshan, but the more I look at it, the more I wonder about it being something else, probably tremolite.

Among the clues are a whitish patch of a somewhat "amphibolian" look and also the cleavage which doesn't fit to diopside.

Any one any insight ?

Thanks ! :)

8th Sep 2016 12:52 UTCAymeric Longi

Although mostly light green, the crystal shows two patches of a different hue. I happen to be sightly colorblind, and I am totally unable to indentify the color with certaintly.

It looks green, but with a light touch of purple... What do you people see ? Is it all green to you ?

8th Sep 2016 13:05 UTCPeter Slootweg 🌟

I think you are right. Not diopside but tremolite. The cleavage angle of 120 is typical for amphiboles and rules out pyroxenes (like diopside).

Peter

8th Sep 2016 13:07 UTCPhil M. Belley Expert

The cleavage angle in photo btr2 will tell you if it is amphibole or diopside. Amphibole, ~120 and 60 degrees. Diopside just off 90 degrees. You'll need a hand lens or microscope.

9th Sep 2016 11:52 UTCAymeric Longi

Greetings Phil & Peter,

Thans for the insight :) Can't see any 90° angle in there, so Tremoite it is!

Cheers! :)

12th Sep 2016 03:18 UTCIan Nicastro

I have an avid interest in this material, and I have a few specimens myself. Mine are a little more grass green then this sample, but the same shape. My matrix piece is in a whiter talc matrix, but I assume this is likely talc as well. I am still trying to get an exact location for this stuff... I have been provided two locations so far, one on each side of the border: Spin Ghar Range in Afghanistan and Kyber Pass area in Pakistan. I sent a really gemmy piece away for analysis and it was confirmed to be Chrome Tremolite by Raman analysis at UCSC geosciences dept. I was told this first started popping up around 2012, then vanished from the market... but recently some more material has been showing up again.

12th Sep 2016 19:44 UTCRob Woodside 🌟 Manager

The tremolite occurs in "white schist" sometimes called talc schist.

12th Sep 2016 23:28 UTCIan Nicastro

Thanks for the clarification Rob!

15th Sep 2016 11:01 UTCAymeric Longi

Ian,

I bought some tremolite in Peshawar in 2007, and I was told they were from Koksha vallley, but I've also seen the same material listed as from Khyber Pass, and also from Gilgit-Baltistan.

The smaller crystals I have are of a darker green color with a waxy/soapy feeling to the touch. Extremely fragile, I've managed to break loose crystals just by holding them... :(

Does your material looks like this one specimen ?

6th Nov 2016 17:10 UTCAnonymous User

I just posted these trying to identify. Found this post and maybe I have the same thing? I'm currently in N Afghanistan. This stuff is all over the ground here.

7th Nov 2016 22:12 UTCIan Nicastro

Chad I am impressed you found fun things in a road gravel quarry. I agree with some of the comments the guys posted on the other thread you also posted these photos on. Not likely to be tourmaline... but Actinolite or Tremolite are definitely possible, those two minerals are closely related and you can even have hybrid crystals that are in between in chemistry. The specimens you have shown are cool, but see if you can find larger individual crystals or gemmy crystals... these would likely occur in little cavities or open veins at the quarry.

Aymeric I just saw your post... the matrix of yours looks the same as my Tremolite. I've seen one other label in the past as claiming one of these Tremolite came from Koksha, but it's not where most of the material I have seen is labeled as originating from. Also the big 2014 Min Rec article on Koksha didn't note any green Tremolite on the market from Koksha at that time, only green Diopside and one dealer had come across yellow Tremolite from there. Below are photos of the two pieces in my collection, the matrix was labeled as Kyber Pass area Pakistan, the gemmier crystal was labeled as from Spin Ghar range in Afghanistan. My friend in Peshawar told me there may be more than one deposit that these are coming from even though they appear similar.

7th Nov 2016 22:13 UTCIan Nicastro

Single crystal. This is the most gemmy one I have seen from this region. This was analyzed by Raman.

8th Nov 2016 00:08 UTCSteven Kuitems Expert

I do. To think you will find the perfect crystals in cavities from these marble sites, virtually all are formed in rock-locked fine grained marble. More perfect crystals most likely came from less deformed areas within the host marble and some can be naturally etched or weathered out of the marble nut I have never seen matrix open pockets containing these species in a marble site BUT you never know...no one has "seen it all"

Steven

8th Nov 2016 07:00 UTCIan Nicastro

I've found small open cavities in skarns before with nicely terminated crystals of various minerals that are found in skarns like Diopside and Epidote and such. Chad's specimens do seem to be in some sort of dolomite marble perhaps, so maybe less likely for little air pockets, but there could be a chance I would think. Some of the nice Tremolites from NY and Canada appear to have had airspace to grow into: http://wheretofindrocks.com/tag/tremolite/

8th Nov 2016 13:44 UTCHarold Moritz 🌟 Expert

Back to the crystal in the original post....it exhibits very obvious parting on {001} (across the prism). This is a property of diopside, not amphiboles. The {110} cleavage of diopside is not as obvious in many crystals as is the {001} parting (leading to much confusion) and the parting is clearly visible in the 3rd photo of the original post. I dont see where the {110} cleavage of amphibole is visible here, though the surface texture in the second photo does look a bit splintery like amphibole. Could this be a tremolite after diopside pseudomorph such as these (though I'm not sure the parting would survive after replacement):

http://www.mindat.org/photo-757955.html

http://www.mindat.org/photo-758037.html

9th Nov 2016 18:40 UTCAnonymous User

Diopside? Also whoever replied about the marble is on to something, seems to be alot of black/white marble here, zebra stripes lol but that is exactly what it looks like.

9th Nov 2016 18:47 UTCAnonymous User

[attachment 67582 IMG_20161109_231344.jpg

Some of the crystals are completely translucent.]

10th Nov 2016 05:51 UTCIan Nicastro

Chad did you find that or purchase it? Great find if you dug that. I can't confidently ID that visually, some crystals look like Diopside in shape, others don't. I'll let one of the crystal angle experts weigh in.

10th Nov 2016 12:38 UTCHarold Moritz 🌟 Expert

Nice looking piece, the overall assemblage looks plausible for either actinolite or diopside, but the photos not nearly close enough to see the crystals well enough. However, the matrix looks fibrous so is likely actinolite and the dark green crystals blockier so more likely diopside. Or the two could be talc and actinolite, respectively.

10th Nov 2016 15:48 UTCAnonymous User

Here's another one, the crystals are dull except for a tiny few. I also found some sort of what looks like muscovite, crocidolite, asbestos based mineral possibly.

10th Nov 2016 16:01 UTCAnonymous User

Here is the asbestos like piece.

Fyi the good looking specimen I did purchase at a bazaar for 40. Probably overpaid but it was interesting and some of the crystals a translucent green. Not sure what the white material/crystalline growths are. There are alot of specimens to be found but im not sure of pricing so haven't bought another. I'll try to post pics of some items for guidance. There is an abundance of lapis lazuli as well. Thanks for all the help btw.

10th Nov 2016 16:02 UTCHarold Moritz 🌟 Expert

Cant tell from the pix, crystals too small, need closeups. Could be actinolite, could be elbaite...

10th Nov 2016 16:19 UTCAnonymous User

A few specimens for purchase.

10th Nov 2016 16:37 UTCAnonymous User

Closer pic

11th Dec 2016 12:14 UTCJoel Dyer

Aymeric, if you have an acquintance who has polishing gear & is trained to use gemmological tools he /she should be able to separate diopside from tremolite-actinolite pretty easily. One always doesn't have to walk down the road of XRD/EDS/Raman/other analysis.

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