Hydrogrossular Value, Price, and Jewelry Information


Hydrogrossular differs from the other garnets in that it is never transparent. It ranges from translucent to opaque. The most common color is a bluish green, but they are also found in pink, white, and gray.

Hydrogrossular Value

The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.

Hydrogrossular Information

DataValue
NameHydrogrossular
Is a Variety ofGrossular
Crystallography Isometric
Refractive Index 1.72 - 1.80
Colors Bluish green, green, pink, white, gray
Fracture Conchoidal, splintery
Hardness 6.5 - 7.5
Specific Gravity 3.40- 3.70
Cleavage None
Dispersion 0.028
Heat SensitivitySome
Transparency Translucent to opaque.
Birthstone January (Garnet)
FormulaCa3Al2(SiO4)3-x(OH)4

Hydrogrossular differs from the other garnets in that it is never transparent. It ranges from translucent to opaque. The most common color is a bluish green, but they are also found in pink, white, and gray.

Because of its coloring and translucency, hydrogrossular is often used as a jade substitute. Large pieces are available, which lend themselves to carving.

Material from New Zealand is known as rodingite (N = 1.702, specific gravity 3.35). So-called Transvaal jade from South Africa occurs in green, gray-green, blueish, and pink colors. Compact and homogeneous, it may have a splintery fracture and waxy luster. The gray material contains zoisite. Pink material, containing Mn, has N = 1.675-1.705 and specific gravity of 3.27. The green, jade-like material has N = 1.728 and specific gravity 3.488.