Quartz
“Earth's most versatile crystal”
Mineral
Quartz is the second most abundant mineral in Earth's continental crust, found in an enormous variety of colors and forms. Its piezoelectric properties — generating voltage under pressure — make it essential in modern electronics and timekeeping.
Composition
silicon dioxide (SiO₂)
Where Found
Brazil, Arkansas (USA), Madagascar, the Alps, Himalayas
Mohs Hardness
7
Fun Fact
Every quartz watch works because a tiny quartz crystal vibrates exactly 32,768 times per second when electricity is applied.
Test Your Knowledge
Why does quartz lack cleavage and instead fracture with smooth, curved surfaces?
Related Specimens
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