"The Mystery of Lyle and Louise"

Fightly cemented, medium-to-coarse quartz grains.

Spinel group; black, dull metallic luster; common iron oxide.

Black, soft; most widely mined.

Pale pink felsite, with small sanidine phenocrysts.

Gray, fine-grained, massive contact rock.

Gray to buff, with numerous ooliths and fossil fragments.

Light gray, fine small clasts.

Dense and massive.

Hematite-cemented quartz; orthoquartzite.

Pure, large, transparent-to-translucent cleavages, Mohs’ hardness of 4.