fluorspar
Concise Oxford English Dictionary © 2008 Oxford University Press:
fluorspar /ˈflʊəspɑː, ˈflɔː-/
▶noun another term for fluorite.
– origin C18: from fluor ‘a flow, a mineral used as a flux, fluorspar’ (based on L. fluere ‘to flow’) + spar3.
'fluorspar' also found in these Oxford entries:

