Slate is usually dark, but it can be colorful too. Slates vary in color and are most common in black, gray, red, purple, or green. The red color is due to the presence of Hematite, while green colors are due to Chlorite. Grey and black are caused by   carbon and/or graphite in the slate. iron oxides are responsible for red, purple, and tan shades. High-quality slate has been used as roofing tiles, paving stone, pool tables, and blackboards. Some of the slate rooftops from 16th century Europe are still in use today which hints at its great durability.
All of the slate used at Slate Products, LLC is diamond drilled using an in-house developed method which assures precision cut pieces and extremely accurate fits.
(We could tell you how its done but then our stonecutter would have to kill you! ;)
		Slate develops geologically from the sedimentary rock, shale. Occasionally  basalt or  other fine-grained rock can metamorphose into slate.   When shale is buried deep underground its clay minerals neomorphose into chlorite and muscovite mica crystals. When these crystals fuse together they form a denser and harder rock along its lateral edge resulting in a material cleavage. This allows it to be split along one plane rather easily but makes it strong in the other plane. Slate is a  metamorphic rock which is formed under relatively low pressure and temperature conditions.
								An abandoned slate quarry in the Huron Mountains of Baraga County