From Frankish *slaitan (to split) via Old French—named for the rock's ability to split into smooth sheets.
A fine-grained metamorphic rock that splits into smooth, flat plates, traditionally used for roofing and writing surfaces.
From Old French 'esclate' (fragment, splinter), from the verb 'esclater' (to shatter, to split), from Frankish *slaitan (to split, to tear). The rock was named for its defining property: it splits cleanly into thin sheets. Key roots: *slaitan (Frankish/Germanic: "to split, to rend").