Quartz, e.g. (7)
I believe the answer is:
mineral
(Other definitions for mineral that I've seen before include "Substance that is (usually) inorganic" , "Gypsum or magnesia, say" , "Valuable ore" , "Ore; soft drink" , "Metal ore" .)
I believe the answer is:
mineral
(Other definitions for mineral that I've seen before include "Substance that is (usually) inorganic" , "Gypsum or magnesia, say" , "Valuable ore" , "Ore; soft drink" , "Metal ore" .)