Muscovite Mica Schist is very silvery from the fine grains of mica oriented roughly parallel It contains small, round, brown garnet crystals Schists have the quality of breaking off in thin layers. Silver flakes can be peeled off with a fingernail.
Biotite Mica Schist is similar to the Muscovite Mica Schist above, but is very dark and lustrous. The dark, sparkly flakes can be peeled off with a fingernail.
Gneiss can be easily recognized by its alternating layers of light and dark, which are formed by heat and pressure. This is a course-textured rock with minerals in parallel streaks of light and dark grey.
Wilson Quartz Diorite has a granite-like texture and is whitish, with very small black crystals. It is also called “salt and pepper” rock because of its black-and-white speckled pattern. Specimens found in Eaton Canyon come from the Mount Wilson area.
Lowe Granodiorite has a granite-like texture and is whitish, with small clusters of black crystals which give it the appearance of a Dalmation. >Specimens found in Eaton Canyon come from the Mount Lowe area.
Hornblende Gabbro has a granite-like texture and is dark gray, with deeply-enmeshed whitish crystals.
Granite Pegmatite is pinkish with white areas, and has a large, angular crystal structure. The pinkish color in this feldspar is due to its potassium content.
Milky Quartz is formed by silica, precipitated out of steam as magma was cooling It is formed of large crystals with flat planes, and is white and nearly translucent. The whitish crystals are nearly translucent.