mineral

Pyrite and Sunstone

Iron Sulfide (FeS2) and Plagioclase Feldspar ((Ca,Na)Al(Al,Si)Si2O8)

AI-generated identification · may be incorrect

Pyrite: Hardness 6-6.5, brassy yellow/gold, metallic luster, cubic system. Sunstone: Hardness 6-6.5, orange-brown, vitreous luster, triclinic system with aventurescence.

Identified March 23, 2026More mineral →

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Physical properties

Pyrite: Hardness 6-6.5, brassy yellow/gold, metallic luster, cubic system. Sunstone: Hardness 6-6.5, orange-brown, vitreous luster, triclinic system with aventurescence.

Formation & geological history

Pyrite forms in hydrothermal veins and sedimentary environments. Sunstone forms in igneous contexts, specifically within basaltic lavas or pegmatites.

Uses & applications

Pyrite is used for sulfuric acid production and ornamental jewelry (marcasite style). Sunstone is primarily a gemstone for jewelry and decorative carvings.

Geological facts

Pyrite is famously known as 'Fool\'s Gold' due to its color. Sunstone\'s shimmer is caused by tiny inclusions of copper or hematite that reflect light.

Field identification & locations

Identify Pyrite by its green-black streak and cubic shape. Identify Sunstone by its internal orange 'glitter.' Commonly found in Peru and Spain (Pyrite) or Oregon, USA and Norway (Sunstone).