Bluish, greenish, grayish, or brownish hard metamorphic rock that breaks into long fragments easily. Slate is hardly soil, or rather crackable rock through which grapevines can squeeze roots in their search for nutrients and hydration. The relative infertility of slate often results in low yields. Slate tends to grow wines associated with firm acidity, power, and a certain smokey quality. Famous regions include Mosel and Priorat.