|
|
| a pure form of finely ground silica | |||
|
|
| variety of silica containing microcrystalline quartz | |||
|
|
| a hard kind of stone; a form of silica more opaque than chalcedony | |||
|
|
| a piece of flint that is struck to light a fire | |||
|
|
| resembling or containing chert | |||
|
|
| pebbles of flint used in masonry construction |