GARNET FAMILY

 

Pictured above (left to right-back row):  1.27 ct Tsavorite, 3.83 ct Malya Garnet, 4.15 ct Rhodolite, 1.71 ct Hessonite, 2.04 ct Spessartite; (left to right-front row): 0.67 ct Mali Garnet, 1.44 ct Pyrope, 1.79 ct Color Change Garnet, 0.95 ct Grossular Garnet, 0.65 ct Demantoid.

Introduction: The garnets are a complex family of minerals, all having similar structures but varying widely in chemical composition and properties. Of the many members of the family, there are five main species (highlighted in bold) seen in the gem trade. There is a solid solution series between certain garnet species but not between others due to specific differences in internal structure. Following is a
listing of the commonly seen garnet species, the solid solution series and their varieties. More info is available under the specific species or variety of garnet.

Pyrope, Mg3Al2Si3O12

Pyrope-almandine solid solution series (varieties: chrome pyrope, rhodolite)

Almandine, Fe3AL2Si3O12

Almandine-spessartine solid solution series

Pyrope-spessartine solid solution series (varieties: malaya, color change garnets)

Spessartine, Mn3Al2Si3O12

Andradite, Ca3Fe2Si3O12 (varieties: demantoid, topazolite)

Grossular-andradite solid solution series (varieties: grandite or Mali garnet)

Grossular, Ca3Al2Si3O12 (varieties: tsavorite, hessonite)