Garnet Var. Uvarovite (Chromium Garnet)
 
Uvaravite, a member of the Garnet group, crystallizes in the form of masses, grains, dodecahedral crystals, trapezohedral crystals, and combinations of dodecahedral and trapezohedral crystals. Uvarovite is the rarest of the common members of the garnet group, and is the only consistently green garnet species. The colour is green is due to the occurence of Chromium. The mineral was first reported in 1832 by H. Hess and was named for Count Sergey S. Uvarov, a Russian statesman and influential minister of education. 
 
Chemical Composition: Ca3Cr2Si3O12
Hardness 6.5 – 7.5
 
"Garnets are found in many varieties, each being described by a special name; the Bohemian Garnet is a deep red, whilst the Cinnamon stone usually has its colour varied by a tinge of orange; Almandines have a violet hue and take their name from Alabanda, a town in Asia Minor, where, according to Pliny, this stone (which he describes as the Alabandicus) was in his time cut and polished. They are found in Brazil, Mexico, Bohemia, Australia, and North America, an uncommon bright green variety being also found in the Ural Mountains. The colour of the best stones approximates to that of the Ruby, fur which it was sometimes mistaken by the Ancients, and amongst modern jewellers it is frequently described as the Cape Ruby, although the Ruby is a much harder stone, richer in colour, and possesses much more fire.
 
Garnets have always been extensively used throughout the East and amongst the Greeks and Romans, the latter frequently using them for engraving, several fine specimens of Imperial portraits having come down to us in this way.
 
In India and throughout Persia it was known as an Amulet against poison and the plague, worn to attract health and cheerfulness, and as a protection against lightning. During the Middle Ages it was used as a remedy for inflammatory diseases, and to confer constancy, fidelity, and cheerfulness to its rightful wearers, but was said to cause discord amongst those having no right to it by birth. Like the Ruby, it warned its owner of approaching danger and trouble by changing its colour, and was much in vogue at one time as a keepsake between friends at parting."
-The Book of Talismans, Amulets and Zodiacal Gemsby William Thomas and Kate Pavitt 1922