Schist

Schists are the next higher grade of metamorphic rock from slates. (Actually, I am skipping phyllites, which should come next, in the interest of simplicity.) Schists have mineral crystals large enough to be identified and usually have wavy, undulating foliation textures caused by micas and other platy minerals. Distinctively metamorphic minerals such as garnet, staurolite, kyanite, and sillimanite occur in schists, depending on the metamorphic grade and starting composition of the parent rock.

This is a schist consisting almost entirely of staurolite and muscovite. Note that some of the staurolite crystals have formed the crosses that distinguish staurolite. Click here for a super close-up of this sample.
In this garnet-staurolite-muscovite schist the staurolites are larger and darker and untwinned (uncrossed). The garnets are deep red. The orangish/reddish color of the muscovite is due to iron staining.
This close-up of a very staurolite-rich schist shows the blocky cross-section that is typical of well-formd staurolite. The garnets are bright red-orange.
This is a garnet-kyanite-quartz schist. The large purple garnets look like candies. The kyanite grains are the bluish gray flat grains found here and there, especially in the top of the photo. Click here for a close-up of the kyanite. Click here for another.
The muscovite is stained orange from iron oxides, but the garnets are still obvious. The muscovite in the middle left looks a bit like kyanite in this photo, but is clearly muscovite in person.
This is a nice garnet-staurolite schist in which some of the staurolites show their characteristic cross-shaped twinning.

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