Fossil Grass is a semi-precious gemstone surface — a Semi-precious gemstone slab built from irregular fossil-like organic chips and slices set in a matrix — dense mosaic of olive-gold, charcoal-brown and cream fragments with dark crackle outlines, reading as a backlit decorative stone surface. slab with a polished finish, often backlit as a feature panel, vanity or bar front. A dramatic decorative stone for interior feature applications.