Slate

Name:
Slate
Detailed information:
A fine-grained metamorphic rock that cleaves into thin slabs or sheets. Color usually gray to black, sometimes green, yellow, brown, or red. Slates are composed of micas, chlorite, quartz, hematite, clays, and other minerals.

Occurrence:

Pennsylvania, Vermont, Maine, Virginia, California, Colorado, Europe.

Use:

Roofing, blackboards; (as powder) filler in paint, rubber, abrasive.