Sponge

About it

Vases, cups, balls, and star-spiked plates riddled with pores and canals, with none of a coral's septa. Silurian Astraeospongia of Tennessee, Devonian glass sponges of New York, and English chalk sponges are well known.

Type

Fossil (other)

Group

Sponge (Porifera)

Colours

grey, tan, brown, white, black

Transparency

opaque

Periods

Ordovician, Silurian, Devonian, Jurassic, Cretaceous

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