Slate Slate Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. It is the finest grained foliated metamorphic rock. Foliation may not correspond to the original sedimentary layering, but instead is in planes perpendicular to the direction of metamorphic compression. The foliation in slate is called "slaty cleavage". It is caused by strong compression causing fine grained clay flakes to regrow in planes perpendicular to the compression. When expertly "cut" by striking parallel to the foliation, with a specialized tool in the quarry, many slates
Slate (magazine) working on a long, ambitious project of some sort," Plotz said in an interview. "Slate" introduced a paywall-based business model in 1998 that attracted up 20,000 subscribers but was later abandoned. A similar subscription model was implemented in April 2001 by "Slate"s independently owned competitor, Salon.com. "Slate" started a daily feature ”Today's Pictures” on November 30, 2005, which featured 15-20 photographs from the archive at Magnum Photos that share a common theme. The column also features two flash animated ”Interactive Essays” a month. "Slate" was nominated for four digital National Magazine Awards in 2011 and won the NMA for General