FAQ’s

BRIEF HISTORY OF SLATE The finest grade of Vermont slate is quarried, milled and distributed by Newmont Slate Company. Withstanding the test of time, this beautiful, durable natural stone, resistant to fire and erosion, has a fascinating history. It is approximately 500 million years old with roots in an even earlier period of the Earth’s evolution. In ancient times, sediments originating once as clay minerals and bits and pieces of eroded rocks carried by water, wind and ice were deposited in horizontal layers at the bottom of the earth’s oceans, lakes, and riverbeds. Over time, these bedding planes compacted and naturally cemented together to form shale. The shale was subjected to conditions

different from those under which it was originally formed. Tremendous geological forces from volcanic activity and continental shifting moved, heaved, and folded the masses containing the shale. Extreme heat, pressure, and varying chemical environments altered the shale’s texture and mineral assemblage at a molecular level. As a result, the shale metamorphosed into slate. Flakes of the mineral mica that were once haphazardly arranged in shale, aligned themselves in parallel planes at right angles to the source of pressure forming slatey cleavage.  Today, this cleavage facilitates ease in hand-splitting the slate during the milling process.