Oolite

Oolite or oölite (from Ancient Greek ᾠόν (ōión) 'egg stone')[1] is a sedimentary rock formed from ooids, spherical grains composed of concentric layers.

Oolites are often used in the home aquarium industry because their small grain size (0.2 to 1.22 mm) is ideal for shallow static beds and bottom covering of up to 1" in depth.

Because of its extremely small grain size, oolitic sand has a lot of surface area, which promotes high bacterial growth.

When the lake drained (2 to 4 million years ago), the oolite was left behind, along with siltstone, volcanic tuffs and alluvium from adjacent mountain slopes.

The physical and chemical properties of the Shoofly Oolite are the setting for a suite of rare plants, which the BLM protects through land use management and on-site interpretation.

Quarries in Oolitic, Bedford, and Bloomington contributed the materials for such U.S. landmarks as the Empire State Building in New York and the Pentagon in Arlington, Virginia.