Synthetic Gem Materials and Simulants in the 1990s
The 1990s witnessed important developments in the commercial viability of gem-quality synthetic diamonds.
Synthetic or imitation? An investigation of the products of Kyocera Corporation that show play-of-colour
An investigation of the difference between synthetic opal and opal simulant.
Dyed Natural Corundum as a Ruby Imitation
The gemmological properties of a new ruby imitation, produced by dyeing natural colourless to pale-coloured corundum, are described.
An Examination of Nontransparent “CZ” from Russia
White, pink and black nontransparent synthetic "cubic zirconia" is currently being manufactured in Russia and marketed primarily in cabochon and bead form.
"Opalite": Plastic Imitation Opal with True Play-Of-Colour
A plastic imitation opal that shows true play-of-colour was advertised as "new" and offered for sale under the trade name "Opalite" at the Gem and Lapidary Dealers Association (GLDA) Tucson show in February 1988.
Inamori Synthetic Cat's-Eye Alexandrite
This article reports on a detailed gemmological examination of this new synthetic cat's-eye alexandrite.
Lepidolite with Simulated Matrix
The authors examine an unusual crystal in matrix.
The Early History of Gemstone Treatments
The author has uncovered many ancient references to the simulation or enhancement of gemstones.
Cobalt Glass as a Lapis Lazuli Imitation
The properties of a novel gemmological imitation, cobalt glass.
The Identification of Turquoise by Infrared Spectroscopy and X-Ray Powder Diffraction
Two techniques for identifying natural, treated and synthetic turquoise are examined.