Quartz-rich sandstone pebble with a natural perforation ("hag stone") — sedimentary Identification & Properties | Geo-Gem
Quartz-rich sandstone pebble with a natural perforation ("hag stone") is a sedimentary. 1) Hand lens: look for distinct rounded sand grains—confirms sandstone. 2) Scratch test: try a steel nail and then try to scratch a piece of glass; quartz-rich sandstone should scratch glass. 3) Acid test: place a drop of 10% HCl (or stron…