Muscovite schist, biotite schist, and chlorite schist (often called "greenstone") are commonly used names. Other names based upon obvious metamorphic minerals are garnet schist, kyanite schist, staurolite schist, hornblende schist, and graphite schist.

Type Metamorphic Rock Texture Foliated; Fine- to medium-grained Composition Muscovite, Biotite, Garnet, Quartz, Feldspar Index Minerals Garnet Color Shiny, medium gray Miscellaneous Small-sized dark red-brown garnets on foliation surfaces Metamorphic Type Regional Metamorphic Grade Middle Grade (Middle P – Middle T) Parent Rock Shale, Mudstone, or …

2023年7月2日 · Garnet Schist is a somewhat rare foliated metamorphic rock that forms when the oceanic crust rubs against the overriding plate as it subducts at subduction zones. The metamorphism is caused by intense pressure but relatively low heat, which can give specimens a strange weak foliation.

Garnet Schist is a type of schist contains garnet, a semi-precious gemstone that can be red, pink, or orange. Garnet schists are often found in high-grade metamorphic zones. Composition: Mica (biotite or muscovite), quartz, feldspar, and garnet (10-20%).

Schist (/ ˈʃɪst / SHIST) is a medium-grained metamorphic rock showing pronounced schistosity (named for the rock). This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes or plates.

A schistose metamorphic rock containing garnet (commonly almandine) and mica.

Schist very commonly contains large inclusions of gem minerals like garnet, kyanite, and staurolite which can make specimens look very different from one another. Since a schist is primarily defined by its texture, it first helps to know what schistose texture looks like.

2023年8月26日 · Garnet Schist: Characterized by the presence of garnet crystals along with other minerals. Quartzite Schist: Dominated by quartz minerals, often with layers of mica or other minerals. Amphibolite Schist: Rich in amphibole minerals like hornblende, contributing to …

Garnet schist (5.5 cm across) has conspicuous, large or small garnet crystals. Garnets in schists are typically very deep red-colored. The surrounding matrix is often a grayish and mica-rich. The garnet-muscovite schist shown above is early Late Cretaceous in age (89 to 92 million years).

Strongly foliated garnet-mica schist from the Monteneve mine, showing extremely cracked almandine porphyroblasts (spotty grey to black), with an inclusion-rich core zone and inclusion-poor rim zone, in a fine-grained matrix consisting of quartz, plagioclase (colorless), biotite (brown), and muscovite (colorless), formed during upper greenschist ...