GIA Gem Encyclopedia | Complete List Of Gemstones
GIA’s Gem Encyclopedia is a virtual journey through the science and lore of gemstones from across the globe. Each precious stone page features additional detailed gemological information, a buyer’s guide, photos, videos & research.
Gem Cutting Styles - Definitions - GIA
2018年8月9日 · GIA researcher and cut expert, Al Gilbertson, examines the elements of cutting, investigates the choices and tradeoffs a cutter makes and why, and provides guidelines for assessing various aspects of cut quality for colored gemstones.
Natural Diamonds | Diamond Stone – GIA C
Diamonds are among nature’s most precious and beautiful creations. Colorless diamonds are scarce—most diamonds have tints of yellow or brown. Factors used to describe diamonds: Clarity, Color, Cut, Carat Weight. The rarity of one or more of the 4Cs can affect value.
View All Gems - Gem Kids - Gemological Institute of America
View All Gems - Gem Kids. GEM EXPLORER. View All Gems Find My Gem. Polished.
Amethyst Gemstone | Amethyst Stone - GIA
The essence of the color purple, amethyst is beautiful enough for crown jewels yet affordable enough for class rings. This 13.44-ct. Zambian gem displays the rich royal purple color typical of fine amethysts. Amethyst is available in many shapes and sizes including antique cuts.
Pearl Gemstone | Pearl Stone | Pearl Gem - GIA
Natural or cultured, saltwater or freshwater, nacreous or not, pearls come in a myriad of shapes and colors, telling the stories of the mollusks in which they grew.
Sapphire Gemstone | Sapphire Stone - GIA
Sapphire is the birthstone for September and the gem of the 5th and 45th anniversaries. Kashmir Intensely saturated and velvety, rare sapphires from Kashmir set the standard for blue.
What Is Tanzanite Gemstone | Tanzanite Stone – GIA
Tanzanite is available in a wide range of shapes but cushion and oval cuts are most common.
What Is Tourmaline Gemstone | Tourmaline Stone - GIA
Tourmalines have a variety of exciting colors with one of the widest color ranges of any gem species, occurring in various shades of virtually every hue.
Ruby Quality Factors | The Color Range of Ruby - GIA
The most common shape is a flat tabular hexagonal shape, but ruby crystals from some sources can be elongated. To accommodate these crystal shapes, the most common shapes of fashioned rubies are ovals and cushions, with brilliant-cut crowns of kite-shaped and triangular facets, and step-cut pavilions with concentric rows of rectangular or ...