Connecticut State Mineral

Garnet

(Almandine garnet)

Adopted in 1977

Named the State Mineral in 1977 by the General Assembly. Connecticut is one of the finest sources in the world of the almandine garnet. An ancient gem, it was named "garnata" in the 13th century by Albertus Magnus, and was known as the "Carbuncle," likening it to a small, red hot coal.
 

Connecticut is one of the finest sources in the world of the almandine garnet, named the state mineral by the 1977 General Assembly. An ancient gem, it was named "garnata" in the 13th century by Albertus Magnus and was known as the "Carbuncle" in its likeness to a small, red hot coal.

The garnets are actually a group of similar minerals, complex silicates of the same atomic structure, but differing in chemical composition. They vary in color from pale to dark tints, including the deep violet-red of the almandine garnet.

This mineral's hardness, 7 on the Mohs scale, has made the garnet useful as an abrasive, resulting in an important industry throughout Connecticut's history. It contributed to this development by providing the base for grinding wheels, saws, and the better cutting quality of garnet paper, a variety of sandpaper.

Physical Characteristics

Almandine garnet is an iron aluminum silicate with a characteristic red color.

Pronunciation: ALL•man•deen GAR•net (accent on capitalized syllable)

Color: deep red to brownish red

Luster: vitreous

Diaphaneity: translucent; may appear opaque in hand specimen

Hardness: 6.5-7.5

Specific gravity: 3.5-4.3

Cleavage/fracture: none (glassy fracture)

Other distinguishing properties: Forms in 12x-sided equant balls. Commonly found in metamorphic rocks, such as garnet shists. Garnets are commonly used as abrasives and in sand paper, because of their hardness.

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