Black Grey Basalt D. G. A Crushed Stone Fines Material. Central California Quarry This is a very attractive black grey crushed basalt stone fine material produced by a quarry in Central California. This crushed black basalt material packs down very well for pathways, patios, and other surfaces where decomposed granite is used. The strong black-grey color of this material provides an extra design element as a contrasting or complementary dark color not often found in landscape materials.
