Spessartine

Spessartine is silicate of manganese and aluminum with the composition Mn3Al2(SiO4)3. The samples at left show the dramatic red-orange color it often exhibits.

This sample of spessartine with muscovite is about 3x3 cm and is from Gilgit, Northern Areas, Pakistan. These samples are displayed in the Smithsonian Museum of Natural History.

This sample is described as spessartine with shorl, albite and quartz. It is about 12x15 cm and is from Hercules mine, Ramona, California.This locality is known for gem-quality orange spessartine, a garnet mineral rich in manganese. The black shorl shows up in dramatic contrast.

This sample is described as spessartine with helvite, quartz, and microcline. It is about 20 cm long and is from Tongbei, Fujian Province, China.

Another example of the habits of formation of spessartine crystals comes from Garnet Hill, White Pine County, Nevada. The sample at right is about 9x7 cm.

These spessartine gems are 40.1 and 26 carats and are from Amelia, Virginia.

Mindat: Spessartine

Grossular

Ca3Al2(SiO4)3

Grossular is silicate of calcium and aluminum with the composition Ca3Al2(SiO4)3. These grossular crystals are from Asbestos, Quebec, Canada. The sample above is about 20 cm across.

This grossular sample is about 6x6 cm and is from Sandave, Nioro du Sahel, Mali.
This grossular sample is part of the mineral collection from the cretaceous period around Crestmore, California. It is about 8 cm across.

This grossular sample is about 10x14 cm and is from La Calera, Cordoba, Argentina.

Mindat: Grossular

Andradite

Ca3Fe2(SiO4)3

Andradite is silicate of calcium and iron with the composition Ca3Fe2(SiO4)3. This sample is about 10x7 cm and is from San Benito County, California.

This sample is described as andradite with clinochlore and epidote. It is about 6x9 cm and is from Marquakhel, Spinnatigga, Parchines, Pakistan.

Mindat: Andradite



Anorthite


CaAl2Si2O8

Anorthite is a silicate silicate of calcium and aluminum with the composition CaAl2Si2O8. This sample is about 8x11 cm and is from Monzoni, Val di Fassa, Trentino-Alto Adige, Italy.

Mindat: Anorthite

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