brown spar is a clear to yellowish to blue mineral that is very soft and not well suited for making of gemstones

alabaster background black blue brown calcite class clear closeup collection color construction crystal cube earth element gem gemstones geological geology gypsum iceland industrial isolated jewelry macro making material mine mineral mineralogy natural not object petrography production rock rough sample satin selenite semiprecious shape shiny soft spar specimen stone structure suited sulfate surface texture that transparent variety very well white yellowish