It looks like marble, but it's actually made of onyx marble dust held together by resin.

The ship was carrying marble dust and was about two and a half miles from shore when she radioed for help.

An iron sheet placed over a dry river bed with marble dust as snow was used to recreate the charge of the partisans across the frozen lake.

Polished plaster itself tends to consist of slaked lime, marble dust, and/or marble chips (which give each plaster its distinctive look).

Sand or marble dust, and lime, were sometimes added.