Coated Beryl Imitating Emerald
Coating on a beryl demonstrates the importance of thorough examination of jewelry and gem materials.
Treated Red and Green HPHT Synthetic Diamonds
Two treated synthetic diamonds, a Fancy red and a Fancy Vivid yellowish green, showed strikingly vibrant colors.
Update on Diffusion-Treated Corundum: Red and Other Colors
Blue diffusion-treated sapphires have become a subject of considerable controversy since their introduction in significant quantities a few years ago.
Treated Pink Type IIa Diamond Colored by Red Luminescence
A type IIa color-treated diamond was graded as Fancy brown-pink under daylight conditions and Fancy purplish gray under incandescent lighting, a color change that resulted from HPHT annealing and irradiation.
The Chinese Red Feldspar Controversy: Chronology of Research Through July 2009
Red copper-containing plagioclase feldspar from Oregon has been available for over a century. In the early 2000s, new localities for copper-bearing feldspar were reported from the Democratic Republic of the Congo and from Tibet or an unspecified locality in China.
Two Treated-Color Synthetic Red Diamonds Seen in the Trade
Two dark brownish red faceted stones, recently submitted to the GIA Gem Trade Laboratory for standard origin-of-color reports, were found to be treated synthetic diamonds.
Treated-Color Pink-To-Red Diamonds from Lucent Diamonds Inc.
Using a multi-step process, Lucent Diamonds has developed a new treatment process for certain natural diamonds that creates colors from pink-purple through red to orangy brown.
An Unusual Filled Ruby
A red specimen, showing properties associated with Burmese ruby, shows a rare method of clarity enhancement.
Irradiated Topaz and Radioactivity
Large quantities of colorless topaz are currently being treated by gamma irradiation to turn them blue.
Diamond, Artificially Irradiated and Coated Brown
Examination of a diamond with a rare and highly sought-after Fancy reddish brown color revealed that it had been irradiated and coated.