🌟 Monthly Mineral Spotlight – July 2025
Calcite: The Chameleon of the Mineral World
From ancient construction materials to modern classroom experiments, calcite is everywhere—and often hiding in plain sight. Known for its dazzling crystal forms and variety of colors, this humble calcium carbonate mineral is a favorite of rockhounds, collectors, and scientists alike.
🧠 What Is Calcite?
Calcite (CaCO₃) is one of the most common minerals on Earth. It forms in sedimentary, metamorphic, and igneous environments and is the primary component of limestone and marble. Its name comes from the Latin calx, meaning “lime.”
Notable traits:
Wide range of colors (white, clear, yellow, orange, blue, green, pink, and more)
Perfect rhombohedral cleavage
Mohs hardness: 3
Reacts strongly (fizzes!) with dilute hydrochloric acid
🔬 Cool Properties & Fun Facts
Double refraction: Transparent Iceland Spar splits light into two images.
Fluorescence: Some calcite glows under UV light.
Crystal habits: Dogtooth, nailhead, scalenohedral, rhombohedral, and more.
Industrial uses: Cement, soil treatment, optical instruments, and more.
⛏️ Why Rockhounds Love Calcite
Occurs with minerals like fluorite, galena, and pyrite.
Found in massive veins, cave systems, and geodes.
Beautiful crystals in many shapes and vibrant colors.
📍 Where to Find Calcite
Elmwood Mine, Tennessee – golden dogtooth calcite
Rossie, New York – transparent crystals
Sweetwater County, Wyoming – classic scalenohedrons
Cave systems across the U.S. – stalactites and stalagmites
Orange Calcite – photo courtesy of Didgeman – Pixabay
Iceland Spar – photo by unknown author – Pixabay