what is flint

Flint is a sedimentary cryptocrystalline form of the mineral quartz, categorized as a variety of chert that occurs in chalk or marly limestone. It is a very durable material that has been used historically to make stone tools and start fires. Flint occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and limestones, and is usually dark grey or black, green, white, or brown in color, with a glassy or waxy appearance. It breaks and chips into sharp-edged pieces, making it useful in constructing a variety of cutting tools, such as knife blades and scrapers. Flint has been used for over 2 million years to make stone tools and weapons, and it is also used to create sparks and as a gemstone. It is occasionally cut into cabochons, beads, and baroque shapes for use as a gemstone and is also used to produce tumbled stones in a rock tumbler. Flint is widely distributed around the world and was a primary material for Stone Age tools and weapons. It is chemically complex, consisting of a fine mosaic of colloidal silica (opal) and crypto-crystalline silica (chalcedony) .