quartzite
/ˈkwɑrtsaɪt/Definitions
1. noun
A type of metamorphic rock composed primarily of the mineral quartz.
“The geologist studied the quartzite formations in the ancient mountain range.”
2. noun
A type of sedimentary rock that consists of interlocking grains of quartz.
“The river flowed over a bed of quartzite, polishing the stones smooth.”