032419

Cross-laminated oolitic dolomitized grainstone, Jurassic, Smackover Formation, porous oil reservoir, North Choctaw Ridge Field, Alabama, five-centavo piece for scale.

Rocks are pretty

 

Thin section photo of a mica flake, viewed with crossed polarizers. Surrounded by calcite cement.

A very poorly sorted sandstone

A sample of beach sand would consist of very round particles all more or less the same size. This one was not deposited on a beach