A sample o Miorcani flint frae the Cenomanian chalky marl layer o the Moldavian Plateau. (ca. 7.5 cm wide)

Flint is a haird, sedimentary cryptocrystalline furm o the meeneral quartz,[1][2] categorized as a variety o chert. It occurs chiefly as nodules and masses in sedimentary rocks, such as chalks an limestanes.[3][4] Inside the nodule, flint is uisually dark grey, black, green, white, or broun in colour, an eften has a glassy or waxy appearance. A thin layer on the ootside o the nodules is usually different in colour, typically white an rough in textur. Frae a petrological pynt o view, "flint" refers specifically tae the furm o chert which occurs in chalk or marly limestane. Similarly, "common chert" (sometimes referred tae simply as "chert") occurs in limestane.