FMF - Friends of Minerals Forum, discussion and message board

[mihailovici79]

Thanks for information. I read also the Mindat post. Indeed it`s very difficult to break the stone with my hammer. I have an very hard hammer.
Yeah, I scratch my wife`s mirror with this piece. I hope she doesn't see that scratch cuz I`m fucked. :). I made this pyramid ;). I'm interested for jade too, especially as I discovered the location with jade in Romania and there is enough jade (nephrite)

[cascaillou]

glass hardness is 5 to 6 (usually 5.5), so if your stone scratches glass, that means it is hardness 5 or higher.

nephrite hardness is 5.5 to 6.5
serpentine hardness is usually 2.5 to 4 but some can be as high as 4 to 5.5 (bowenite)

the best way to make sure would be to place a tiny polished piece of the mineral (with flat and smooth facet) on a refractometer, as serpentines RI range is quite different from nephrite RI range. I can do that for you if you want.

[mihailovici79]

Thanks. Where are you from? We can talk about this. If you visit my blog you can see more details.

[cascaillou]

Well that's up to you, it's only if you're interested in idenifying your stone more precisely.

A tiny 4 millimeters sized sample would be more than enough for this purpose, but it would have to be perfectly polished, meaning that it needs to have a perfectly flat facet cut (not curved) with a very smooth surface. You would have to do the cutting and polishing as I haven't got the tools to do it myself.

By the way, don't send me anything bigger, because I won't send it back to you: once I'm finished with the analysis, I will just discard the sample (so a 4 mm sized granule is all I would need, don't send anything of any value so I don't need to send it back)

As that would be a very small sample, you could send it in a simple envelope. I'm in France.

I can't be sure I will succeed in getting a refractive index from the sample, that depends on the polishing, I'm not a jade expert but I can try and if I can get any results I would report on the forum.

Otherwise, the easiest way to go would be to bring a small polished piece to a jeweller near where you live, and ask him if he could measure the RI for you.

EDIT: I just visited your website, I can see that many of your stones are labelled as serpentine, so you actually know what they are?

[mihailovici79]

Yeah.I`m working very much with serpentine and jade for jewelry and decorative objects.
Regarding the rock sample can be solved because my sister is a student in Clermont and I`ll send you a piece of jade. Thank u again

[cascaillou]

It's ok for me. But I insist: a tiny 4mm sized piece is enough (not bigger!). Need it cut and very well polished, with flat and smooth surface.
You could send the envelope directly to my address in Paris.

[Tracy]

Perhaps this conversation could continue by private message? Still too early for cascaillou, but mihailovici79 can send a pm to set up a less public exchange.

- Tracy

[Jordi Fabre]

[mihailovici79]

ok sorry about this

[mihailovici79]

Jade the other nuance of color. Jade Romania ft Amethyst Brasil

[cascaillou]

I received your private message with your email address, I'll keep in touch.

[cascaillou]

As we had agreed, Mihail gave me two mineral samples, which I analysed today.

Here's the first mineral:
https://imageshack.us/photo/my-images/69/dsc00104mz.jpg/
https://img69.imageshack.us/img69/7788/dsc00104mz.jpg

And here's the second mineral:
https://imageshack.us/photo/my-images/820/sdsc00102.jpg/
https://img820.imageshack.us/img820/195/sdsc00102.jpg
(links normalized by FMF)

Fisrt mineral:

definately looks like a garnet with pinkish color, the crystal is roughly isometric.
Hardness is 6 or 6.5
Polariscope gives it as isotropic.
Specific gravity is about 4.06
Spectrum confirmed that it is indeed a garnet.

Second mineral:

Weighs 29.58g
It is green and transluscent, with greasy luster. Some white veins are present.
The white veins instantly react to concentrated hydrochloric acid with effervescence (I guess these are calcite), however the green material remains unattacked after 24hours of soaking in HCl.
In transmitted light one can see that the inner world of the stone is cloudy, with cloudy structures sometimes arranged as bands (thus imparting somewhat of a banded appearance to the stone). Under stronger magnification, tiny inclusions of shiny black platelets can be seen in the mix.
Fracture is slightly splintery.
Hardness is 5 or 5.5
Streak is white.
Specific gravity is 2.56
Polariscope gives it as a microcrystalline aggregate.
Refactive index is about 1.558

From the above data, it should be serpentine (note that I didn't search for treatments).

[mihailovici79]

Thank you for your analysis. I have a question:why is so hard this serpentine? I know that the serpentine has 2.5 - 4 Mohs hardness.

Best regards.

Mihail

[cascaillou]

well serpentine are actually a group of several closely related minerals. Most have a hardness from 2.5 to 4 but some (such as the bowenite variety) are 4 to 5.5
I guess it is best to have the harder kind as it will better handle wear.

[mihailovici79]

:) Yeah you`re right