Glass Imitation Of Cat’s-Eye Chrysoberyl

A very common imitation for chrysoberyl cat's eye is glass. The phenomenal effect is not natural-looking for a trained eye. Many thanks to gemologists at GIA Hong Kong for sharing the report.

Useful link:

https://www.gia.edu/gems-gemology/summer-2023-lab-notes-glass-imitation-cats-eye-chrysoberyl

Glass Imitation Of Star Sapphire

Glass is the best imitation for colored stones. Product knowledge and standard gemological tests should easily separate natural blue star sapphires from imitations. 

Useful link:

https://www.gia.edu/gems-gemology/fall-2021-glass-imitation-star-sapphire

Boron Carbide: A New Imitation Of Black Diamond

Take a look.

Useful link:
http://www.gia.edu/gems-gemology/FA13-GNI-boron-carbide-diamond-imitation

How To Spot A Fake Diamond

Take a look.

Useful link:
http://www.bloomberg.com/video/how-to-spot-a-fake-diamond-oA6SJqGDRBOFEyCx3pQNIQ.html

How To Spot A Fake Diamond

A must read.

Useful link:
http://www.wired.co.uk/magazine/archive/2013/07/how-to/spot-a-fake-diamond

Costume Jewelry Update

Randy Molofsky's report was interesting. Many thanks.

Useful links:
http://www.jckonline.com/2012/05/19/get-your-costume-jewelry-fix
http://fragments.com
http://www.greenwichjewelers.com
http://www.houseoflavande.com
http://www.jwjewelers.com

Man-made Diamonds

The Economic Times article on man-made diamonds was interesting. Synthetic diamonds are created in a laboratory. They have nearly the same chemical, physical, and optical properties of their natural counterpart. On the other hand, imitation diamonds usually resemble in color only. They do not have the same chemical, physical and optical properties of their natural counterpart. In fact synthetic diamonds and imitation diamonds often get mixed up. I think imitation/synthetic diamonds are not that difficult to identify. If doubtful always consult a reputed gem testing laboratory.

Useful links:
http://www.ckcsons.com
http://www.popleys.com
http://www.debeers.com
http://www.debeersgroup.com
http://www.moissaniteco.com

Gemstone Information Manual

Gemstone Information Manual provides industry information for natural gemstones, enhanced natural gemstones and man-made stones. Check it out. www.agta.org

Random Thoughts

Back in the day, there were women who would only wear the real deal, but now it's really hip to wear costume jewelry.

- Paula Correri
www.tobereport.com

Spot on.

Bill Cunningham Viewpoint

On the Street / Fashion Fireworks
http://www.nytimes.com/interactive/2009/07/02/fashion/20090705-street-feature/index.html?hp#

Gigantic fake jeweled necklaces — sparkling like fireworks — are just the thing to cheer up last year’s dress. Great imitations, really. Thanks Bill.

Cubic Zirconia Phenomenon

'Rock' Bottom
http://www.nypost.com/seven/04122009/news/regionalnews/rock_bottom_164082.htm

People are looking for inventive ways to cut costs. I think cubic zirconia is the best imitation gem around.

Nanocrystalline Diamond-Coated Cubic Zirconia

A new cubic zirconia coated with nano-diamond treatment has been launched by Zirconmania in Los Angeles, U.S.A. The gem material not only improves the optical and physical properties of CZ, but also becomes an ideal alternative to diamond/moissanite. Visual identification may be difficult so do not rapid sight identify without proper testing procedures. If doubtful always consult a reputed gem testing laboratory.

Useful links:
www.zirconmania.com
www.diamondveneer.net
www.zirconite.com

Cubic Zirconia Masters In Diamond Color Grading

A place for CZ masters in diamond color grading
- Michael D Cowing
The Journal of Gemmology/2008/Volume 31/ No.3/4

Abstract: Over the last 20 years and despite recommendations to the contrary, many gemologists are appraisers have gravitated to the use of cubic zirconia (CZ) master stone sets to assist in the color grading of diamonds. This investigation revisits with new insight, diamond grading technique and methodology. It addresses the judicious use of CZ master stone sets to augment diamond masters that are smaller in size and number. Study results support the use of accurately graded, carat-size CZs in reducing the subjectivity of color grading when only incomplete (every other grade) diamond master sets of small (under 0.4 ct) sizes are available.

Useful link:
www.gem-a.com

I think it was interesting to learn why CZ masters have found a place in the color grading of diamonds in the trade/labs. If effectively used/periodically checked for retention of accuracy CZ masters are practical/functional.

Look-alike Jewelry

Keeping Up Appearances
http://www.newsweek.com/id/178821

Useful links:
www.kennethjaylane.net
www.justingiunta.com
www.subversivejewelry.com
www.bagborroworsteal.com
www.gilt.com
www.yoox.com

Great essay. Thank you Sameer. My view is social climbers will go the extra mile to put forth a prosperous image regardless of the balance in their bank account(s). It's a state of mind.

Imitation Turquoise

(via Wikipedia) The Egyptians were the first to produce an artificial imitation of turquoise, in the glazed earthenware product faience. Later glass and enamel were also used, and in modern times more sophisticated ceramics, porcelain, plastics, and various assembled, pressed, bonded, and sintered products (composed of various copper and aluminium compounds) have been developed: examples of the latter include "Viennese turquoise", made from precipitated aluminium phosphate coloured by copper oleate; and "neolith", a mixture of bayerite and copper phosphate. Most of these products differ markedly from natural turquoise in both physical and chemical properties, but in 1972 Pierre Gilson introduced one fairly close to a true synthetic (it does differ in chemical composition owing to a binder used, meaning it is best described as a simulant rather than a synthetic). Gilson turquoise is made in both a uniform colour and with black "spiderweb matrix" veining not unlike the natural Nevada material.

The most common imitation of turquoise encountered today is dyed howlite and magnesite, both white in their natural states, and the former also having natural (and convincing) black veining similar to that of turquoise. Dyed chalcedony, jasper, and marble is less common, and much less convincing. Other natural materials occasionally confused with or used in lieu of turquoise include: variscite and faustite; chrysocolla (especially when impregnating quartz); lazulite; smithsonite; hemimorphite; wardite; and a fossil bone or tooth called odontolite or "bone turquoise", coloured blue naturally by the mineral vivianite. While rarely encountered today, odontolite was once mined in large quantities—specifically for its use as a substitute for turquoise—in southern France.

These fakes are detected by gemmologists using a number of tests, relying primarily on non-destructive, close examination of surface structure under magnification; a featureless, pale blue background peppered by flecks or spots of whitish material is the typical surface appearance of natural turquoise, while manufactured imitations will appear radically different in both colour (usually a uniform dark blue) and texture (usually granular or sugary). Glass and plastic will have a much greater translucency, with bubbles or flow lines often visible just below the surface. Staining between grain boundaries may be visible in dyed imitations.

Some destructive tests may, however, be necessary; for example, the application of diluted hydrochloric acid will cause the carbonates odontolite and magnesite to effervesce and howlite to turn green, while a heated probe may give rise to the pungent smell so indicative of plastic. Differences in specific gravity, refractive index, light absorption (as evident in a material's absorption spectrum), and other physical and optical properties are also considered as means of separation. Imitation turquoise is so prevalent that it likely outnumbers real turquoise by a wide margin. Even material used in authentic Native American and Tibetan jewellery is often fake or, at best, heavily treated.
http://en.wikipedia.org/wiki/Turquoise

Today China has become an important source for imitation turquoise. The opaque bead materials are mass produced, inexpensive, and found in gem markets worldwide. If in doubt, always consult a reputed gem testing laboratory.

Alexandrium

Li Al Silicate (+Nd) + Amorphous (glass) + Light blue to lavender + Hardness = 6.5 + Heat sensitive + perceived as simulants for many light blue colored stones (especially alexandrite).