Phosphorite

About it

Sedimentary rock rich in apatite, often dark, pelleted or nodular, and full of bone, teeth, and fish scales; it can carry traces of uranium. Mined for fertilizer in Florida, Morocco, and the Phosphoria Formation of Idaho.

Type

Rock (sedimentary)

Group

Sedimentary (chemical)

Lustre

dull, earthy

Colours

brown, black, grey, cream

Transparency

opaque

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