New York Bluestone New York Bluestone (also known as Pennsylvanian Bluestone) is a natural cleft sandstone used for patios, walkways and flooring. Strong and durable, it is available in a natural irregular shaped flagging or sawed in dimensional tiles. Quarried in both New York and Pennsylvania, Bluestone takes its name from the deep blue color of the original stone layers quarried. Bluestone is not limited to just the blue color, but comes in a mixture of a variety of colors from green, gray, reddish brown and lilac with striations of gold, purple and brown.   Dimensional Bluestone Patio Photo Courtesy of Fox Chase Landscaping, Inc.   Approximately 360 million years ago during the Devonian Period, the Acadian Mountains were being eroded away. This material high in quartz, feldspar, sand and mica was deposited in a narrow band across the southern end of New York State and the northeastern part of Pennsylvania. This deposit known as the "Catskill Delta" is the birth place of bluestone. Formed in slow moving water, the eroded material was laid down in thin deposits showing the ripples and flow of the water over its surface. Over time, these layers coalesced into a strong sandstone known as a feldspathic greywacke. Eventually this stone was quarried and the thin layers (known as reeds) were split apart revealing the ancient delta surface and becoming New York Bluestone.   Irregular Shaped Bluestone Flagging Photo Courtesy of Fox Chase Landscaping, Inc.