Rock Specimens

Dense and massive.

Black, soft; most widely mined.

Black, fissile; commonly with carbonized fossil plant impressions.

Buff, coarse, crystalline “Austin Marble” with shell casts and molds.

White, mature, friable.

Gray to buff, with numerous ooliths and fossil fragments.

Light gray, fine small clasts.

Red, medium, to coarse-grained iron oxide cement; shows hematite bands.

Gray with line crinoid columnal fragments.

Light gray, earthy.