a microcrystalline form of silica usually occurring as bands or layers of pebbles in sedimentary rock. Formula: SiO2. Varieties include flint, lyddite (Lydian stone)
Also called: hornstone
Derived forms
cherty (ˈcherty)
adjective
Word origin
C17: of obscure origin
chert in American English
(tʃɜrt)
noun
an extremely dense type of quartz, including jasper and flint, having a dull, opaque luster and made up of microscopic crystals