Translucent calcite crystals with chalcopyrite on pink matrix from USA.
Full specimen of clear calcite crystals on pink rhombohedral matrix, USA.
Close-up of colorless calcite prisms containing brassy chalcopyrite inclusions, USA.
Detailed macro of clear calcite crystals over peach rhombohedral matrix, USA.
Macro view of translucent scalenohedral calcite crystal with internal chalcopyrite, USA.
Macro photograph of peach rhombohedral calcite matrix with brassy chalcopyrite, USA.

Chalcopyrite, Calcite & Dolomite

Chalcopyrite – CuFeS2
Elements: Copper, Iron, Sulfur
Class: Sulfides
Crystal System: Cubic
Hardness: 3.5-4
Fluorite
Talc (1)Diamond (10)
Softer than glass. A steel knife scratches it.
Calcite – Ca(CO3)
Elements: Calcium, Carbon, Oxygen
Class: Carbonates
Crystal System: Hexagonal
Hardness: 3
Calcite
Talc (1)Diamond (10)
A copper coin can scratch it.
Dolomite – CaMg(CO3)2
Elements: Calcium, Magnesium, Carbon, Oxygen
Class: Carbonates
Crystal System: Hexagonal
Hardness: 3.5-4
Fluorite
Talc (1)Diamond (10)
Softer than glass. A steel knife scratches it.
Origin: Peru
Did you know?

Brassy and gold-flecked, chalcopyrite is the single most important source of copper on Earth, the ore behind most of the metal in modern wiring.

Look through a clear rhomb of Iceland spar calcite and the world doubles, split into twin images by the crystal's double refraction. Some researchers think Norse sailors used this very effect to find the sun through cloud, the so-called sunstone, though the idea remains a debated hypothesis.

Dolomite builds entire mountain ranges, including the Italian range named after it, yet almost never forms in today's seas and resists easy growth in the lab. Geologists still call this the dolomite problem.

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