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
Inanimate whose the English Language" of 1860: "At present, the use of "whose", the possessive of "who", is pretty generally confined to persons, or things personified, and we should scruple to say, 'I passed a house "whose" windows were open.' This is a modern, and indeed by no means yet fully established distinction." Henry Bradley in the "Oxford English Dictionary" asserted "usually replaced by "of which", except where the latter would produce an intolerably clumsy form". Other grammarians began noticing discrepancies between usage and the assertions of those who prescribed against the inanimate "whose". The American Goold Brown, in his "The Grammar