sand - coarse beach sand with a high percentage of glass grains - 250 ml display bottle with ground glass stopper 400 feet thick

400 feet thick

oolitic sand from Great Salt Lake

and they range from faint to obvious

these larger student specimens are from a vein with some attached quartz or wall rock

then roughly 160 million years later weathers to become sand again

sand - coarse beach sand with a high percentage of glass grains - 250 ml display bottle with ground glass stopper 400 feet thickFor years residents at Ft. Bragg, California threw their trash over the bluff into the Pacific. Cars, old shoes, everything. Some time ago the trash was almost all cleaned up, but the glass remained to become part of the sand. Glass Beach is a part of a state park, where collecting is not permitted. However, the longshore current moves sand southward along the coast in California, and small coves south of the park have a high percentage of glass