Calcite

Calcite is a carbonate mineral found as part of Amethyst Geodes.

Natural generation
Calcite generates naturally as part of the structure of Amethyst Geodes, between the Tuff and Amethyst Block layers.

Breaking
Calcite drops as an item if mined by any pickaxe. If mined by any other tool, it drops nothing.

Usage
Calcite is currently used only for decoration.