If you were born in the month of June, you are lucky enough to have three birthstones to call your own. June is one of only three months (the others are August and December) that has three birthstones ...

During the past 25 years, the corundum market has been transformed from one of medium to high-priced gems to one that encompasses nearly all price ranges. This transformation was caused by the ...

Since late 2007, rubies and sapphires have been mined by hand methods from both eluvial and primary deposits at Winza in central Tanzania. The gem corundum is related to “dikes” of amphibolitic rocks ...

Brazil is currently the leader in overall production of amethyst. This article describes the author's visits to three of Brazil’s most important mining areas: Marabá, Pau d’Arco, and Rio Grande do Sul ...

The various techniques in use today to alter colorless topaz to produce brown, pink, and most commonly, blue stones are discussed. Special attention is given to the three irradiation sources -gamma ...

A necklace of round beads offered as "blue quartz from India" was analyzed by gemological and additional advanced techniques. The violet-blue ornamental material, which resembled fine-quality lapis ...

This note deals with some gemological applications for a tool well known to microscopists: the first-order red compensator. In gemological microscopy, the compensator can be useful in locating ...

The discovery of significant quantities of gem-quality sapphire in Minas Gerais could add corundum to the formidable list of gem species already commercially produced in Brazil. The presence of ...

Blue sapphires are currently being mined on an exploratory basis from alluvial deposits at the Lindi mine, near the town of Mingxi in Fujian Province. The geology and occurrence of the sapphires ...

The refractive indices of the synthetic overgrowth on the beryl seeds of Lechleitner synthetic emeralds show a linear correlation with the chromium content of the coating. In a sample with refractive ...

Established in 1931, the Gemological Institute of America (GIA) is the world’s foremost authority on diamonds, colored stones, and pearls. A public benefit, nonprofit institute, GIA is the leading ...

A synthetic gem material is one that is made in a laboratory, but which shares virtually all chemical, optical, and physical characteristics of its natural mineral counterpart, though in some cases, ...