Pyrite (Fool's Gold)

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal Structure: Isometric/Cubic; Cleavage: Poor/Indistinct; Specific Gravity: 4.8-5.0

Forms in a variety of geological environments including sedimentary deposits, hydrothermal veins, and as an accessory mineral in igneous rocks. The specimens shown appear to be weathered nodules or aggregate clusters.

Primarily used in the production of sulfur dioxide for the paper industry and sulfuric acid for chemical applications. In jewelry, it is often sold as 'marcasite'. It is a popular mineral for beginner collectors.

Pyrite is nicknamed 'Fool's Gold' because its color and high specific gravity can lead inexperienced prospectors to mistake it for real gold. It is distinguished from gold by its brittleness and much higher hardness.

Look for its brassy metallic luster and cubic crystal habits in the field. It often occurs in coal beds and sedimentary shales. These specific specimens are small, weathered fragments found alongside shark teeth (fossils), indicating they were likely gathered from a beach or a Miocene-age creek bed.