Garnet geological occurrence and geological implications

Geological occurrence:
The pyrope production in the ultrabasic rocks eluvial placer, a large grain of gem-quality pyrope rare. The former Soviet Union, Norway, the Czech Republic and China Jiangsu are outputs; magnesium iron garnet mainly from the United States and the United Republic of Tanzania and other countries; the almandine Dan Shengcheng in the mica schist and amphibolite gneiss metamorphic rock and placer among Origin Sri Lanka, Brazil, Madagascar, India and other countries; calcium aluminum garnet skarn product, but also found in the alteration of serpentinite and gabbro bring, such as Kenya, Pakistan, but the former Soviet Union and output green grossular. Hessonite production from Sri Lanka; spessartine production in pegmatites, some metamorphic rocks have appeared, the production of gem-quality manganese aluminum garnet stone from Myanmar, Sri Lanka, Brazil and other countries; andradite is gray schist and metamorphic product of the rock band, was brown and green demantoid and yellow garnet stone production serpentinite black garnet stone production in the rich alkaline igneous rocks in the former Soviet Union and the Congo are output; Uvarovite is a gas into a hot aqueous solution with calcium ultrabasic rocks of the product, the former Soviet Union and the United States have been found.
Geological meanings:
Garnet group is the use of the lithospheric thermal dynamics to understand a key minerals of igneous and metamorphic origin. The speed of diffusion of elements in the garnet and other minerals compared to relatively slow, and garnet relative resistance metasomatism. Therefore, the individual can be saved their internal composite tape garnet is used to understand its Language rock temperature change history. And not garnet composite tape will be understood as diffusion lead to uniformity, because the more impact single situation can also be used to infer the history of living in the rock temperature changes.
Formation conditions:
Garnet metamorphic rock has its function. Eclogite can be defined as a rock of basalt composition, but mainly constituted by garnet and green pyroxene. Containing a larger proportion of pyrope garnet can only be produced in a relatively high-pressure metamorphic rocks, for example, in the bottom of the crust and mantle rocks. Peridotite may contain plagioclase, or rich in aluminum spinel, or rich pyrope garnet, the three minerals exist at the same time confirmed the olivine and pyroxene mineral balance pressure temperature zone. The above three minerals peridotite mineral assemblage, in the case of pressure increase its stability to arrange. Garnet peridotite may only deep in the crust. Garnet peridotite xenoliths from Kimberley rock from 100km
Or deeper is brought up, and by xenoliths debris contained in the garnet is used as a diamond indicator mineral exploration in the Kimberley rock. Depths of 300 to 400km and more, component pyroxene (Mg, Fe) and Si-substituted dissolved in a regular octahedron in the garnet (Y) location 2Al garnet, manufacturing a silicon content of unusually high garnet, and the nature of the solid solution as magnesium iron garnet. This high silicon content of garnet is confirmed to be included in diamonds.