As the Paleozoic Era came to an end, the continents were squeezed by rocks beneath the oceans. They pushed the hardened sea muds upwards, shoving and crumpling them into huge, high folds. When the shales were squeezed into sharp folds, pressure became so great that they raised nearly 6 miles of rock above them crumpling the top most shale into mountains. The intense heat and pressure generated caused many particles to recrystallize and flatten, often at right angles to direction of compression. Slate is chiefly comprised of quartz and illite, with mica, calcite, and minor quantities of other various minerals.
Slates vary in color, most commonly seen in black, gray, red, purple, or green.
Red color is due to the presence of Hematite, while green colors are due to Chlorite. American Slate Company has the largest inventory and range of natural colors of the finest domestic and international slates and quartzites and the largest selection of natural slate roofing and floor tiles in a range of over fifty natural colors from around the world. Roofing slate is available in standard and rough texture in a wide range of colors. The variety of material, plus the ability to machine gauge, will fit almost any project requirements. We would like to extend an invitation to you to visit one of our facilities to see our broad range of colors and textures.