Abstract/Description: SiO2 - Mohs Hardness: 7. Quartz is the source of most of our society's glass- from windowpanes and crystal goblets to eyeglasses and cathedrals' stained glass windows. It is one of the most common minerals because it is chemically and physically stable at Earth's surface conditions. Quartz was the mineral upon which the Stone Ages were based. With few exceptions, most early stone tools were fashioned of quartz. Outcrops of quartz that were suitable for tool manufacturing were targeted by some of the earliest known mining activities and the mined quartz was traded across vast distances.
Subject(s): Arkansas, United States
environmental sciences