Almandine
Salida, Colorado

This specimen measures 5cm in diameter




Garnet group     
     Mg3Al2Si3O12(pyrope)
     Fe3Al2Si3O12(almandine)
     Mn3Al2Si3O12(spessartine)
     Ca3Al2Si3O12(grossular)
     Ca3Fe2Si3O12(andradite)
     Ca3Cr2Si3O12(uvarovite)

Nesosilicates; aluminum and calcium silicates

Color and Luster: Vitreous; colorless streak
Pyrope is a deep red to reddish black,
(Var. Rhodolite)
is a puple or rose to pale purplish red
Almandine is a deep red to brown, brownish black
Spessartine is a brownish red to hyacinth-red
Grossular
is colorless, white, yellow, pink, green, or brown
Uvarovite is emerald green
Andradite
is wine-red, greenish(Var. demantiod), yellow (Var. topazolite), brown, or black(Var. melanite)

Hardness: 6.5-7.5

Cleavage: None; parting sometimes distinct in six directions

Fracture: Conchoidal, uneven, brittle

Crystals: Isometeric; crystals very common as dodecahedrons and trapezohedrons; also granular, lamellar, compact, disseminated


Photo by Mary Sutherland


Descriptions taken from
The Audubon Society Field Guide to North American Rocks and Minerals