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
Alan (given name) Iranian "*aryāna", "noble people") because the long vowel in the second syllable would produce Old Breton "-o-", Middle Breton "-eu-" and Modern Breton "-e-" and not the attested spelling with an "-a-". In Ireland and Gaelic-speaking Scotland, Alan may also be an Anglicization of an Irish word (with diminutive suffix) meaning "rock". For example, the modern Irish "ailín" means "little rock". Similarly, according to Patrick Woulfe, the Irish name "Ailín" is derived from diminutive "ail", which means "noble", "rock". Woulfe stated that this name is a pet form of some other name beginning with the first element "Ail-". Forms of