◂ BACK TO GEM ENCYCLOPEDIA
Sapphire
The name “sapphire” can also apply to any corundum that’s not ruby red, another corundum variety.
See Gem As
Tools
Research
Gemstone Enhancement and its Detection in the 2000s
Advances in technology and increased demand for lower-priced gem materials contributed to the proliferation of new treatments throughout the first decade of the 2000s.
Purplish Pink Spinel from Tajikistan: Before and After Cutting
In November 2008, the Bangkok laboratory was fortunate to have an opportunity to briefly examine seven stones that the client had faceted from this parcel.
Ruby and Sapphire Production and Distribution: A Quarter Century of Change
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.
Rubies and Sapphires from Winza, Central Tanzania
Since late 2007, rubies and sapphires have been mined by hand methods from both eluvial and primary deposits at Winza in central Tanzania.
Beryllium Diffusion of Ruby and Sapphire
The heat treatment of corundum involving lattice diffusion of beryllium (Be) at temperatures over 1800°C has become a major issue in the gem trade.
Sapphires from Antsiranana Province, Northern Madagascar
Since 1996, large quantities of yellow to blue sapphires have been recovered from alluvial deposits derived from basaltic rocks in northern Madagascar.
The Separation of Natural from Synthetic Colorless Sapphire
Greater amounts of colorless sapphire—promoted primarily as diamond substitutes, but also as natural gemstones—have been seen in the gem market during the past decade.
Sapphires from the Andranondambo Region, Madagascar
Since 1993, large amounts of gem-quality sapphires from the Andranondambo region of southern Madagascar have entered the international gem market.
The Yogo Sapphire Deposit
Yogo Gulch, discovered more than 100 years ago, is one of four major sapphire-producing areas in Montana, United States.
Ruby and Sapphire from the Southern Ural Mountains, Russia
Primary occurrences of ruby, pink sapphire, sapphires of other colors, and spinel have been found in marbles in the Ural Mountains.
Heat Treating the Sapphires of Rock Creek, Montana
Renewed interest in large-scale commercial mining of Montana sapphires motivated a detailed study of the heat treatment of sapphire from the Rock Creek deposit.
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.
