Hydrogrossular

Hydrogrossular is a calcium aluminium garnet series. It found in massive crystal habit, sometimes grown in with idocrase.

Hydrogrossular is a garnet variety in which a Si4+ is missing from a tetrahedral site. Charge balance maintained by bonding a H+ to each of the four oxygens surrounding the vacant site.

Hydrogrossular is translucent to opaque, and found in green to bluish green, pink, white, and gray. The cause of the green color is chromium, and possibly iron. Pink caused by the presence of manganese. It may have dark gray to black small inclusions. It has similarities to jade, and has the misnomers Transvaal jade, and African jade.