Cosmos is a schist that contains quartz, mica, feldspar, garnet and biotite. The shiny flecks of mica give this stone a unique look. Because the areas containing mica are not as hard as the other minerals, fabricating the edge detail can be difficult. Due to the varying degrees of hardness throughout the stone, it is normal to have some chipping and waving. A flat or beveled edge detail will show less waving in the final installation. Additionally, the softer areas are more prone to scratching. Cosmos is not recommended for use around spas or in excessive wet areas. During the polishing process, an epoxy resin is applied to the surface of the stone to fill in any natural pits, cracks or fissures that may exist. This does not affect the durability, maintenance or beauty of the stone. It is possible for some of the more minute pits that are too small to effectively hold the resin, to reopen during other finishing stages. However, this will not detract from the overall quality or appearance of the stone.

This granite is also known as Black River.