Andradite is a mineral with a hardness of 7 out of 10 on the Mohs scale of mineral hardness [?]. These Cubicly structured gems are made of calcium iron silicate, their full chemical compound being Ca3Fe2(SiO4)3.

Andradite is a name given to members of the garnet that contain manganese and titanium. The 3 types Andradite are..1.)Demantoid, 2.)Melanite, and 3.) Topazolite

Demantoid-the word means diamond like. It is yellow green to green in color and is the most valuable of the 3 types. Demantoid is soft enough that older gems will have facet edges that are slightly worn. Largest deposits have been found in the United States, China, and Russia.

Melanite-also called Black Melanite is black (duh), looks like black glass, and like Demantoid, Melanite is soft enough that older gems will have facet edges that are slightly worn.

Topazolite-Like Demantoid and Melanite Topazolite is soft enough that older gems will have facet edges that are slightly worn. Topazolite gets it's name from its similarity to Topaz.

Andradite has the ability to separate light into more colors than even the mighty diamond. If you are hunting for this gem check near metamorphosed limestone deposits.

The specific gravity [?] for Andradite is 3.85, it's refractive index [?] is 1.85-1.89, and it's double refraction [?] is None.


Andradite is named after mineralogist Jose Bonifacio de Andrade, and it was first recorded in 1868 in Norway.

Industrial Usages

Garnets in general are good abrasives for sand blasting, and cutting of steel via pressurized water jets. Fine powdered versions of garnet can be found along shorelines in large quantities.

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Grossular Garnet

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Double Refraction or dr is the ability of a mineral to separate a refracted ray of light into 2 rays. If held over an image or text it will display the object 2x its original size.

Mohs Scale of Mineral Hardness is the standard used to categorize a mineral's ability to resist scratching. It gets its name from Friedrich Mohs, the German geologist who first created the scale.

RI or Refractive Index defines light's ability to move through the mineral or in a general sense, any material.

SG or Specific Gravity is the ratio of the weight of any substance to that of pure water at temperature of 3.98°C(39.2°F) and standard atmospheric pressure. This is important to note when actively seeking these minerals in the wild. Minerals with a higher SG will settle below material with a lower sg over time.