Post subject: Are These Faux Chrysoberyl Cat's Eyes or What? SILLIMANITE!
Posted: Mon Nov 08, 2010 11:08 pm
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Joined: Mon Nov 08, 2010 8:15 pm Posts: 9
Hi,
I bought this necklace at a consignment shop and it was labelled as Chrysoberyl, but it looks like glass to me. However, each stone in the necklace is a different size, depth, and shape than the others, so I am confused why so much work would go into making them. The color is more beautiful dark greens with pink and purple highlights than the photos show. Quite a mysterious, dramatic, and extraordinary piece whatever it is. The backs of each stone are rounded and unfinished, not glossy polished like the front, but light can pass through them.
Any help identifying the stones would be most welcome. Thanks!
Post subject: Re: ?? Are These Faux Chrysoberyl Cat's Eyes or Something El
Posted: Tue Nov 09, 2010 4:03 am
Moderator
Joined: Thu Dec 13, 2007 3:42 pm Posts: 4091 Location: the Netherlands
Chatoyant glass is quite easily identified, immerse the chain in water and have a look at the side of the beads. You should be able to see a honeycomb structure on the sides perpendicular to the direction of the 'eye' if it's glass. Glass feels warm to the touch compared to chrysoberyl and may feature a (cut through) air bubble or two here and there.
Post subject: Re: ?? Are These Faux Chrysoberyl Cat's Eyes or Something El
Posted: Tue Nov 09, 2010 9:01 am
New to the Forum or The Quiet Type
Joined: Mon Nov 08, 2010 8:15 pm Posts: 9
Thanks so much for your advice. I do not see the features you note, but this may be a much earlier and more crude attempt to fabricate the stone, if it is glass.
Post subject: Re: ?? Are These Faux Chrysoberyl Cat's Eyes or Something El
Posted: Tue Nov 09, 2010 9:41 am
Moderator
Joined: Thu Dec 13, 2007 3:42 pm Posts: 4091 Location: the Netherlands
and the touch test?
hold one of the stones against your upper lip, then do the same with a glass object. Have a piece of known crystal (no matter what) handy to compare... does the stone feel cold like the crystal or relatively warm like the glass?
Post subject: Re: ?? Are These Faux Chrysoberyl Cat's Eyes or Something El
Posted: Tue Nov 09, 2010 11:12 am
Gemology Online Veteran
Joined: Sun Oct 07, 2007 2:04 pm Posts: 623 Location: Southern OK/North TX
Tim wrote:
and the touch test?
hold one of the stones against your upper lip, then do the same with a glass object. Have a piece of known crystal (no matter what) handy to compare... does the stone feel cold like the crystal or relatively warm like the glass?
Right on Tim! I carry a small glass flat bead separator ring in my purse that will let me do this test right there before I buy.....
This does look like a lot of work for glass but then there's people like me that also like glass.... That is one beautiful piece! Thanks for sharing it.
Post subject: Re: ?? Are These Faux Chrysoberyl Cat's Eyes or Something El
Posted: Tue Nov 09, 2010 2:00 pm
Valued Contributor
Joined: Tue Mar 23, 2010 8:46 am Posts: 114 Location: Dubai
usamatana wrote:
Hi,
I bought this necklace at a consignment shop and it was labelled as Chrysoberyl, but it looks like glass to me. However, each stone in the necklace is a different size, depth, and shape than the others, so I am confused why so much work would go into making them. The color is more beautiful dark greens with pink and purple highlights than the photos show. Quite a mysterious, dramatic, and extraordinary piece whatever it is. The backs of each stone are rounded and unfinished, not glossy polished like the front, but light can pass through them.
Any help identifying the stones would be most welcome. Thanks!
Northeast Novice
uhmmm...i would take a RI with spot method...and maybe describe the inclusions you see through the stones..you say they transmit light...the "rounded and unfinished" cut suggests something natural to me...sillimanites? just an option...what is making the cat's eye? tubes? needles? let us know
Post subject: Re: ?? Are These Faux Chrysoberyl Cat's Eyes or Something El
Posted: Tue Nov 09, 2010 8:47 pm
New to the Forum or The Quiet Type
Joined: Mon Nov 08, 2010 8:15 pm Posts: 9
Thanks so much, everyone. I'm googling about sillimanite and this does seem to describe what I've got. "Sillimanite is seldom transparent. However, a deposit in Mogok, Myanmar (formerly Burma) yielded lovely and rare violet-blue facet-grade crystals. The pale blue to colorless material from Kenya matches the Burmese material in quality, but the crystals from Burma tend to be smaller in size. The gem gravels of Sri lanka yield rare greyish-green, transparent, and fibrous chatoyant stones. Collectors search for these transparent varieties of sillimanite because the material is so rare."
I'm totally novice and a bit broke. Can anyone give me an idea what it would cost to get a base identification of the stones so I know what I'd be in for?
I'll be sure to post the final word when I get it.
Post subject: Re: ?? Are These Faux Chrysoberyl Cat's Eyes or Something El
Posted: Wed Nov 10, 2010 10:04 am
New to the Forum or The Quiet Type
Joined: Mon Nov 08, 2010 8:15 pm Posts: 9
Thanks for looking and advising. Some of the stones appear treated because there is a circle the cat's eye moves through. Also, the backs of the stones might have been treated to make them irridescent, although alternatively it could be that they were never finished for some reason.
I guess I'll have to pull the money together for an appraisal. I'll post the answer.
Post subject: Re: ?? Are These Faux Chrysoberyl Cat's Eyes or Something El
Posted: Wed Nov 10, 2010 2:29 pm
Gemology Online Veteran
Joined: Wed Dec 30, 2009 11:44 am Posts: 525 Location: PAKISTAN-Peshawar
Dear folks,
Commercial quality cat's eye chrysoberyl can be treated by irradiation. In 1998, hundreds of carats of cat's eye chrysoberyl were sold in Bangkok, Thailand and around the world.
Detection: Unusual color and Geiger counter because these chrysoberyl were highly radioactive.
The true cat's-eye is cymophane, a variety of chrysoberyl, a mineral resembling beryl in containing the element glucinum (beryllium), but otherwise distinct. Chrysoberyl is devoid of silica, which beryl possesses, and is, theoretically, composed of glucina, 19.8 and alumina, 80.2.
Among the numerous minerals which when fibrous, or cut across the cleavage and convex, will exhibit the opalescent ray resembling the contracted pupil of the eye of a cat, are beryl, corundum, crocidolite, dumortierite, quartz, filled with pecicular crystals or fibrous minerals, such as actinolite, byssolite, or hornblende; hypersthene, enstatite, bronzite, aragonite, gypsum, labradorite, limonite, and hematite. These may be opaque, translucent, or transparent and of any colour or colours. Perhaps the commonest of these minerals is the quartz cat's-eye, which falls far short of rivalling the brilliancy and soft colouring of cymophane. The shades of this variety of quartz are greenish, yellowish-grey, and brown. Simple tests will distinguish this mineral from cymophane, as its hardness is but 6 to 7 and its specific gravity, 2.6. This quartz melts with soda to a clear glass, is soluble in hydrofluoric acid, and is not dichroic; its chief components are silicon and oxygen. Cut en cabochon, a band of light appears across the parallel fibres of asbestos which the quartz contains.
Post subject: Re: ?? Are These Faux Chrysoberyl Cat's Eyes or Something El
Posted: Wed Nov 10, 2010 3:37 pm
New to the Forum or The Quiet Type
Joined: Mon Nov 08, 2010 8:15 pm Posts: 9
Thank you both so much. This is quite an education. I'm very worried about the irradiation possibility. The stones are clear like glass with the oddity being that the backside is not polished and clear. The backsides are, however, convex and irregularly shaped, colored, and textured.
Hopefully, tomorrow a visit to a gemologist will provide an answer to this mystery.
Post subject: Re: ?? Are These Faux Chrysoberyl Cat's Eyes or Something El
Posted: Fri Nov 12, 2010 3:09 pm
New to the Forum or The Quiet Type
Joined: Mon Nov 08, 2010 8:15 pm Posts: 9
My local jeweler who travels every year to Eastern Europe to buy stones says that these are definitely not glass, they are very old/antique, hand shaped, and that the backside is just caked body oils, skin, etc. that have accumulated over a century. He believes they are real, but antique, Chrysoberyl.
Next step early next week will be to spend the money to get them assessed by a certified gemologist. Will let you know the final determination then.
Have you checked to see if they change colors in different lighting , sounds like it maybe alexandrite catseyes , if thats the case and only IF , you found yourself a treasure
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