Cochise College          Photos of Minerals

                          Geology Home Page                

                          Roger Weller, geology instructor

                                  copyright 2007-R.Weller

Mineral Information on:

Chemical Group:    silicate

Chemical Formula:     Garnet is
R3''R2'''(SiO4)3  (general formula)

Almandite is Fe3Al2(SiO4)3       Pyrope is Mg3Al2(SiO4)3
Spessartite is Mn3Al2(SiO4)3      Grossulariteis Ca3Al2(SiO4)3
Andradite is Ca3Fe2(SiO4)3        Uvarovite is Ca3Cr2(SiO4)3

Color: red, dark red, reddish brown, brown, green, gray, pink    

Streak:  white or lighter shade of solid color


Hardness:  7 to 7.5         Specific Gravity:  3.6 to 4.3                Fracture:

Cleavage:   none

Crystal Forms: Isometric system
     Crystals are usually dodecahedrons or trapezohedrons or modifications of these two shapes.

Mineral Associations:  Garnets are found in metamorphic rocks.

Identifying Characteristics:  color and crystal shape

Uses:  gemstones and abrasives

Occurrences: Czechoslovakia; in the USA Gore Mountain in New York 

Toxicity:      when-swallowed- low           when inhaled- high

Additional Information:  The ancient name for garnet was carbuncle.