Dyed Yellow Beaded Freshwater Cultured Pearls Imitating South Sea Cultured Pearls
A yellow cultured pearl necklace is compared to the work of a producer specialising in freshwater pearls of all colours.
Colourful Chatoyant Glass
A devitrified glass reminiscent of Victoria Stone is seen during the Tucson gem shows.
Imitation Rubellite Boulders
Specimens presented as rubellite tourmaline rough are found to be resin imitations with lead inserts.
Coated Rock Crystal Imitation of Ruby
A coated rough rock crystal resembles a purplish red ruby.
Serpentine Cabochon with Unusual Olive Green Colour
A green cabochon from China resembling jadeite is found to be antigorite, a member of the serpentine group.
Dyed Green Marble Imitating Jadeite
What appeared to be high-quality jadeite was actually dyed green marble with calcite as the main mineral.
Dyed Marble as a Purple Sugilite Imitation
Investigation of a purple bangle identified it as a dyed marble imitation of sugilite.
Dyed Bone as a Red Coral Imitation
A specimen presenting as red coral is revealed to be dyed bone.
Composite amber with an unusual structure
This 9.12 gram amber composite featured a combination of natural and imitation amber, accompanied by natural and artificial insect inclusions.
Boron Carbide: A New Imitation of Black Diamond
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.