Marcassite France Ref127

Marcassite from Cap Blanc Nez in northern France.

Stone dimensions: L: 42mm x W: 28mm x H: 28mm.>

Weight with base: 117g.

Marcassite is an iron sulfide, known for its golden metallic appearance: it can be confused with pyrite due to its similar chemical composition (FeS₂) and metallic luster.

Unlike pyrite, which has a cubic structure, marcasite forms in the orthorhombic system, giving it distinctive and often radial crystal shapes. This mineral is highly sensitive to humidity and air, which can cause it to break down into iron sulfate and sulfuric acid. For this reason, marcasite specimens must be stored in dry, airtight environments.

Color: Pale gold to brass-yellow.

Hardness: 6 to 6.5 on the Mohs scale.

Density: Approx. 4.8 to 4.9 g/cm³.