Množina: flints

ETYM AS. flint, akin to Swed. flinta, Dan. flint; cf. Old High Germ. flins flint, German flinte gun. Related to Plinth.
Compact, hard, brittle mineral (a variety of chert), brown, black, or gray in color, found in nodules in limestone or shale deposits. It consists of fine-grained silica, SiO2 (usually quartz), in cryptocrystalline form. Flint implements were widely used in prehistory.
When chipped, the flint nodules show a shell-like fracture and a sharp cutting edge. The earliest flint implements, belonging to Paleolithic cultures and made by striking one flint against another, are simple, while those of the Neolithic are expertly chipped and formed, and are often ground or polished.
The best flint, used for Neolithic tools, is floorstone, a shiny black flint that occurs deep within the chalk.
Because of their hardness (7 on the Mohs' scale), flint splinters are used for abrasive purposes and, when ground into powder, added to clay during pottery manufacture. Flints have been used for making fire by striking the flint against steel, which produces a spark, and for discharging guns. Flints in cigarette lighters are made from cerium alloy.
City in Michigan, US, on the Flint River, 90 km/56 mi NW of Detroit; Automobile manufacturing is the chief industry but it is declining.
A hard kind of stone; a form of silica more opaque than chalcedony.

1. Having austere inflexibility; SYN. granitic, unyielding.
2. Showing unfeeling resistance to tender feelings; SYN. obdurate, stony.
Unyielding; stern