Iron Pyrite is commonly called "fool's gold" because it has a warm yellow color and glitters and sparkles like gold. Formed over 100 million years ago by sulfur reacting with iron, these cubic specimens of FeS2 are still being found in the sedimentary limestone and sandstone of the Navajan region of Spain.
Common tests to distinguish iron pyrite from gold:
• Gold does not form a cubic crystal
• Gold is very soft and will bend or break when stabbed with a straight pin; the much harder pyrite will not.
• Gold is not attracted to a magnet; pyrite is.
Pyrite Cube
Single Cube, ca. 2.5 cm, 1.0" per side, 90 g.
Pyrite in Matrix
One or more cubes in sandstone, ca. 1 cm cube in a 2 x 3 cm matrix, 35 g.
Pyrite Penetration Twins
All of the unique specimens are natural pyrite penetration twins - one cubic structure growing from the surface or edge of another. The two crystals share lattice points, but have grown in different directions. These beautiful specimens show sharp twinning and crisp edges. The faces show fine ridges (striations). ca. 3 cm, 30 g.
Large Specimen of Pyrite Cubes in a Matrix - Availability may be limited.
Multiple cubes in a large piece of sandstone. (10 x 10 x 12 cm, 921 g) Contains over 10 pyrite cubes.