Quartz

Silicon dioxide

One of Earth's most common minerals and a master of crystal shapes.

Brazil

Sample content • provenance shown broadly for demonstration

At a glance

Fast Facts

SiO₂

Mohs 7

Trigonal

Brazil

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The Story

Quartz forms when silicon and oxygen atoms lock into a strong repeating structure. It grows in cooling magma, hot mineral-rich veins and sedimentary rocks, making it one mineral with many geological homes.

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Where Does It Fit?

FormulaSiO₂

Crystal systemTrigonal

FormationCrystallises from magma or mineral-rich fluids