amethyst - crystal clusters - set of five student specimens from Brazil The water depth there during

The water depth there during the Pleistocene was 900 feet

but they are decent student specimens at a decent price

The plant produced various salts from brines pumped from below the surface of Searles Lake

Lake Otero evaporated

amethyst - crystal clusters - set of five student specimens from Brazil The water depth there duringAmethyst quartz SiO2 These amethyst crystal clusters formed as linings in gas bubbles in the Parana flood basalts in Rio Grande do Sul province, Brazil. Recent 40Ar 39Ar dating shows these basalts erupted over a roughly 2 million year period beginning 135 1 million years ago. The Parana Etendeka flood basalts cover an extensive area in southern Brazil and parts of Uruguay, Paraguay and Argentina in South America and in Namibia and Angola in