Minerals identify

Know how to recognize them

Hydrogrossular

Nesosilicate

Hydrogrossular is a calcium garnet series (formula: Ca3Al2(SiO4)3−x(OH)4x, with hydroxide (OH) partially replacing silica (SiO4)). The endmembers of the hydrogarnet family (grossular ) depend on the degree of substitution (x): * grossular: x = 0 * hibschite: 0.2 < x < 1.5 * katoite: 1.5 < x < 3.

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

Hydrogrossular is found in massive crystal habit , sometimes grown in with idocrase

Hydrogrossular is translucent , and found in green to bluish green, pink, white, and gray. The cause of the green color is chromium. Pink hydrogrossular is caused by the presence of manganese. Hydrogrossular may have dark gray to black small inclusions., and has the misnomers

Hydrogrossular is sometimes used as a gemstone , being cabochon. Sources for green and pink hydrogrossular are South Africa , and the United States. White hydrogrossular is sourced from Burma

Identification

Color of mineral

Green
Pink
White
Grey

Mohs scale ( mineral hardness )

7

Density ( specific gravity )

1.81

Luster ( interacts light )

Vitreous

Crystal ( diaphaneity )

Cubic