What is "andradite"

n. A nesosilicate mineral of the garnet group with chemical formula Ca₃Fe₂Si₃O₁₂.

n. a garnet consisting of calcium iron silicate and having any color ranging from yellow and green to brown and black; used as gemstone

Andradite is a species of the garnet group. It is a nesosilicate, with formula CaFeSiO.

Andradite includes three varieties:

• Melanite: Black in color, referred to as "titanian andradite".
• Demantoid: Vivid green in color, one of the most valuable and rare stones in the gemological world.
• Topazolite: Yellow-green in color and sometimes of high enough quality to be cut into a faceted gemstone, it is rarer than demantoid.

It was first described in 1868 for an occurrence in Drammen, Buskerud, Norway. Andradite was named after the Brazilian statesman, naturalist, professor and poet José Bonifácio de Andrade e Silva (1763–1838).