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Starburst Stone is a colorful new devitrified glass.

Colourful Chatoyant Glass

Nathan Renfro, August 7, 2017

A devitrified glass reminiscent of Victoria Stone is seen during the Tucson gem shows.

Coated Rock Crystal Imitation of Ruby

Nazar Ahmed Ambalathveettil and Mohamed Karam, November 23, 2015

A coated rough rock crystal resembles a purplish red ruby.

Uneven color and blemishes on low-quality cultured pearl necklace.

Dyed Yellow Beaded Freshwater Cultured Pearls Imitating South Sea Cultured Pearls

Lore Kiefert and Pierre Hardy, August 7, 2017

A yellow cultured pearl necklace is compared to the work of a producer specialising in freshwater pearls of all colours.

Imitation Rubellite Boulders

Emanuele Costa and Raffaella Navone, January 27, 2017

Specimens presented as rubellite tourmaline rough are found to be resin imitations with lead inserts.

Serpentine Cabochon with Unusual Olive Green Colour

Yanjun Song and Lu Zhang, November 23, 2015

A green cabochon from China resembling jadeite is found to be antigorite, a member of the serpentine group.

Dyed Bone as a Red Coral Imitation

Gagan Choudhary, July 25, 2014

A specimen presenting as red coral is revealed to be dyed bone.

Dyed marble imitation of purple sugilite

Dyed Marble as a Purple Sugilite Imitation

Ke Yin and Shan-shan Du, January 30, 2015

Investigation of a purple bangle identified it as a dyed marble imitation of sugilite.

Dyed Green Marble Imitating Jadeite

Larry Tai-An Lai, January 30, 2015

What appeared to be high-quality jadeite was actually dyed green marble with calcite as the main mineral.

Imitation Larimar

Lore Kiefert

One of these contributors (PG) recently acquired a 3.91 ct drop-shaped cabochon, purchased in India as a Larimar imitation, that consisted of a ceramic material.

This 1.04 ct black submetallic round brilliant, initially represented as diamond, was identified as boron carbide. Photo by G. Choudhary.

Boron Carbide: A New Imitation of Black Diamond

Gagan Choudhary, October 17, 2013

The Gem Testing Laboratory in Jaipur identified a black diamond-like specimen as boron carbide, a ceramic material typically used in nuclear, military, and aerospace applications.

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Gemstones

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Gemstones

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