Siberian Amy: Revisiting

Ux4 · Gemology Online Veteran Joined: 16 Oct 2005 Posts: 935

Thought I would throw up a couple of nice amy pics. I hope that you do not throw up when you see them!

Click pic to ENLARGE

Trillions ~3.5ct each.

Has anyone got a trusted source for such stuff that they will share? We have discussed the problem of synthetics previously. These stones are natural, but my source is no longer available. The trillions are the best that I have ever seen, with the one on the left the better of the two. That spot is jus dirt! What is current retail on such material? I would not be willing to let these go for "GUIDE" based retail margins. You?
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Ux4 ... Mo' later

John M. Huff
CenSat Enterprises

africanuck · Posted: Mon May 15, 2006 7:26 am Post subject:

When I read the title of your post, I thought to myself for a second that you had gotten yourself a Russian mail-order bride, lol!

Can't be of much help for the amethyst, but they really are beauties! Do they flash blue AND red, as it appears in the pictures?

Ux4 · Gemology Online Veteran Joined: 16 Oct 2005 Posts: 935

Nuck...

...the Siberian mail-order bride was a dog! A little husky, as a matter of fact. Plus, she was a little ruff around the hedges and could not stand this southern heat. She did not think it cool after I sheared her and left in search of a more pleasant environment! Ingrate! Ahhh, but the memory of her jumping in my lap, in my bed - licking me incessantly; slipping under the sheets; that cute little growl she couldn't supress when biting my toes...well, I better stop now.

...yes, the amy's flash all kinds of blues and reds! Brilliant flashes from the deep purple.
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Ux4 ... Mo' later

John M. Huff
CenSat Enterprises

gemstone90 · Posted: Wed May 17, 2006 1:52 am Post subject:

I have a Siberian amethyst with weight of 91.4 cts, this is one the biggest Siberian amethyst I have seen. Its hue is from violet to reddish purple, dark tone and strong saturation, with some small inclusions and gaseous-liquid inclusions.
I have taken some photos for it, the photos are as follows.
http://www.raresphene.com/photo2/2434.jpg
http://www.raresphene.com/photo2/2432.jpg
http://www.raresphene.com/photo2/2435.jpg
http://www.raresphene.com/photo2/2365.jpg
http://www.raresphene.com/photo2/2380.jpg
http://www.raresphene.com/photo2/2381.jpg
http://www.raresphene.com/photo2/2382.jpg

It has strong pleochroism, when viewed from one side, it shown in photo 2380 appears dark violet, and shown in photos 2434 and 2435 appear violetish blue flash, when viewed from another side, it shown in photo 2381 appears reddish purple, and shown in photo 2432 appears red flash.

The photos 2365, 2380, 2381 and 2382 are taken in room, the light sources from outside the window.
The photos 2432, 2434 and 2435 are taken in room, the light sources from outside the window and a table lamp.

pt · Posted: Wed May 17, 2006 8:06 am Post subject:

Thanks for sharing those stones guys -- it's nice to see some high-class amethyst. And special thanks to you gemstone90 -- it's very helpful to see those girdle & pavilion shots!

I'm curious -- do you understand "Siberian" to denote a color of amethyst or strictly an origin? I have seen plenty of "Siberian" amethyst at shows, etc. that originated out of Uruguay. (Honest dealers usually say Siberian-like, or simply Uruguayan)

How do you distinguish Siberian color/origin from other amethyst of similar hue, tone & flash?
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Peter Torraca, GG
gemcutter
http://www.torraca.net
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gemstone90 · Posted: Wed May 17, 2006 11:22 am Post subject:

Dear Peter, thank you for your praise. "Siberian amethyst" is a kind of high quality amethyst, with reddish purple or purple red hue, dark tone, strong saturation, red flash or red and violetish blue flash. Nowadays, it is a jewelry trade designation – the gems of this quality don't necessarily come from that remote and cold region, it is from Brazil, Uruguay, Bolivia, Zambia, USA (Four peaks, Arizona), China (Liaoning, and Xinyi, Jiangsu), Korea (Unyang amethyst mine), and other countries, of course, the yield is quite exiguity.
I collect some the amethyst, they are from Xinyi and Liaoning (China).
http://www.raresphene.com/Siberian%20amethyst.htm

pt · Posted: Wed May 17, 2006 11:48 am Post subject:

That's roughly how I understood the phrase -- though I was hoping that the material actually orginiating from Siberia had a defining characteristic. (e.g., byssolite horsetails seperate Russian demantoid from demantoid from other locals).

This discussion brings to mind a recent article in Lapidary Journal about Georgia Amethyst -- the deposit there is quickly rising in reputation, at least among collectors. I haven't gotten my hands on any yet, but the article says: "the best Georgia material produces strong, fine, blue fire, equal to the finest, brightest blue in tanzanite. The blue fire sets these Georgia stones apart from those of all other localities known to me, period." (LJ, May 2006, p.60.)

This sounds fantastic (especially since the local is open to collectors on a fee-for-dig basis!). Has anyone seen any of this material? Anyone have a chance to compare it to other amethyst?
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Peter Torraca, GG
gemcutter
http://www.torraca.net
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pt · Posted: Wed May 17, 2006 12:51 pm Post subject:

forgot to mention -- the Georgia amethyst locale has a website: http://www.dixieeuhedrals.net/
_________________
Peter Torraca, GG
gemcutter
http://www.torraca.net
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gemstone90 · Posted: Wed May 17, 2006 10:11 pm Post subject:

Amethyst with blue fire? Yes, this sounds fantastic. The amethyst with violet hue and dark tone, if it with strong pleochroism too, it will show blue flash, as the amethyst appears.
http://www.raresphene.com/photo2/2434.jpg
The deep color amethyst from Liaoning or Xinyi have some tiny red hairy inclusions almost always, this is a characteristic.

pt · Posted: Thu May 18, 2006 7:40 am Post subject:

Yeah, I noticed that from your earlier pic post -- that's one reason why I was curious about the GA material, especially with regard to how it compares.

I can't tell if your blue flash is a reflection from the surface of the stone or transmitted from within -- but assuming it's from within, maybe it could be oriented by the cutter to show the blue face-up. If that is possible, I wonder how it is different from the GA material.
_________________
Peter Torraca, GG
gemcutter
http://www.torraca.net
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Ux4 · Gemology Online Veteran Joined: 16 Oct 2005 Posts: 935

gemstone90...great pics and info!

pt...thanks for the info on the GA material. I haven't seen any yet, but hope to get a sample. The finest material, imho, should have the blue, reddish, and blue-violet flashes emminating from a deep purple body. When you see the good stuff, you will know!

I mentioned earlier that a huge problem with amy's is the prevelance of synthetics in the marketplace and the difficulty distinguishing the fake from the real.

Barbra mentioned that she acquired a niceky colored stone, only to find it synthetic. BTW, Barbra, how did you distinguish the fake?
_________________
Ux4 ... Mo' later

John M. Huff
CenSat Enterprises

gemstone90 · Posted: Thu May 18, 2006 10:29 pm Post subject:

gemstone90 · Posted: Fri May 19, 2006 1:46 am Post subject:

Barbra Voltaire · Posted: Fri May 19, 2006 12:20 pm Post subject:

To answer UX4's question about detecting natural and synthetic amethyst:

The best way, that Im aware of, to separate natural from synthetic amethyst is on the basis of twinning.

Synthetic amethyst first became available in the early 70’s. And it has always posed a challenge to separate synthetic from natural as so many natural specimens are also free from internal inclusions.

Most natural amethysts show examples of repeated twinning on the Brazil Law. Synthetic amethysts are usually grown as one single crystal, and show no twinning at all.

Using the crossed polaroids on a polariscope, one can readily see evidence of twinning, especially if you immerse the amethyst in benzyl benzoate. A twinned stone will show interruption in the spectral rings:

An untwined amethyst will show undisturbed spectral rings. In order to see the spectral rings, one has to orient the stone in the direction of its optic axis.

There is an exception (as usual). The Japanese synthetic amethysts DO show a type of twinning, BUT the twinning seen in these specimens is distinctly different from Brazil twinning. The Japanese synthetic twinning, appears irregular, like small arrowheads or flames.

I could only find one picture to snatch online of the Brazil twinning in amethyst (above), but there is an excellent article in the Fall 86, G&G that is loaded with pics and examples:
"A Simple Procedure to Seperate Natural From Synthetic Amethyst on the Basis of Twinning", by Robert Crowningshield, Cornelius Hurlbut & C.W. Fryer.