Nummulite

About it

Large coin-shaped foraminifera, a few millimetres to several centimetres across, that show a tight spiral of tiny chambers when split. The Eocene limestone of Egypt's pyramids is full of them.

Type

Fossil (microfossil)

Group

Foraminifera (protist)

Colours

grey, cream, tan, white

Transparency

opaque

Periods

Paleogene

Typical values: real specimens vary. For more, see mindat.org.