Garnet is a group of minerals that have been used since the Bronze Age as gemstones and abrasives. Today, it is widely known as the birthstone for January. Garnets are most often seen in red, but are available in a wide variety of colors spanning the entire spectrum. The name "garnet" comes from the Latin granatus ("grain"), possibly a reference to the malum granatum ("pomegranate"), a plant with red seeds similar in shape, size, and color to some garnet crystals.
Six common varieties of garnet are recognized based on their chemical composition. They are pyrope, almandine or carbuncle, spessartite, grossularite (varieties of which are hessonite or cinnamon-stone and tsavorite), uvarovite and andradite. The garnets make up two solid solution series; 1. pyrope-almandine-spessarite and 2. uvarovite-grossularite-andradite.
Six common varieties of garnet are recognized based on their chemical composition. They are pyrope, almandine or carbuncle, spessartite, grossularite (varieties of which are hessonite or cinnamon-stone and tsavorite), uvarovite and andradite. The garnets make up two solid solution series; 1. pyrope-almandine-spessarite and 2. uvarovite-grossularite-andradite.
Physical Properties
Appearance
Garnets are available in many colors including red, orange, yellow, green, blue, purple, brown, black, and colorless. The rarest of these is the blue garnet, discovered in the late 1990s in Bekily, Madagascar.It is also found in some parts of the United States, Russia and Turkey
It changes color from blue-green in the daylight to purple in incandescent light, as a result of the relatively high amounts of vanadium (about 1 wt.% V2O3). Other varieties of color-changing garnets exist. In daylight, their color ranges from shades of green, beige, brown, gray, and blue, but in incandescent light, they appear a reddish or purplish/pink color. Because of their color changing quality, this kind of garnet is often mistaken for Alexandrite.
Garnet’s light transmission properties can range from the gemstone-quality transparent specimens to the opaque varieties used for industrial purposes. The mineral’s luster is categorized as vitreous (glass-like) or resinous (amber-like).
Appearance
Garnets are available in many colors including red, orange, yellow, green, blue, purple, brown, black, and colorless. The rarest of these is the blue garnet, discovered in the late 1990s in Bekily, Madagascar.It is also found in some parts of the United States, Russia and Turkey
It changes color from blue-green in the daylight to purple in incandescent light, as a result of the relatively high amounts of vanadium (about 1 wt.% V2O3). Other varieties of color-changing garnets exist. In daylight, their color ranges from shades of green, beige, brown, gray, and blue, but in incandescent light, they appear a reddish or purplish/pink color. Because of their color changing quality, this kind of garnet is often mistaken for Alexandrite.
Garnet’s light transmission properties can range from the gemstone-quality transparent specimens to the opaque varieties used for industrial purposes. The mineral’s luster is categorized as vitreous (glass-like) or resinous (amber-like).
Source from Wikipedia
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