Feldspar vs. Quartz: What's the Difference? 5 Crucial Signs
WEBSep 2, 2020 · Both feldspar and quartz can form gemstones, but of 200+ recognized gemstones, at least twelve are varieties of quartz, while only four are feldspar. Part of what makes quartz varieties more likely to be considered gemstones than feldspar is their hardness. While soft minerals can be beautiful, they become less valuable if they .