Pyrite Worry Stone

Pyrite is an iron sulfide and can oxidize, tarnish, or crumble if kept damp, so store it dry and away from water. Do not make direct-immersion elixirs from it, and wash your hands after handling raw specimens.

Pyrite forms where iron meets sulfur under pressure, in hydrothermal veins threaded through rock, in the dark of sedimentary beds, and in the heat of metamorphic change. It grows into startlingly precise cubes and radiant suns, its geometry so clean it looks engineered rather than grown. Found from the cliffs of Great Britain to the mines of Spain, Peru, and Chile, it has been prized since antiquity for the fire hidden in its metallic face.

Pyrite is iron sulfide (FeS2), the most abundant sulfide mineral on Earth. It crystallizes in the isometric (cubic) system, forming cubes, pyritohedrons, and octahedrons, and carries a bright metallic luster in a pale brass-yellow to golden hue. With a Mohs hardness of 6 to 6.5 and a high specific gravity of about 5.0, it is notably heavy for its size. Its greenish-black streak and brittleness distinguish it from the soft gold it so often imitates.

• The Greeks named it from pyr, meaning fire, because struck against metal or flint it throws a spark, and early peoples carried it as a fire-starter and a stone of the hearth.
• The Inca polished large slabs of pyrite into mirrors, using their reflective faces for ceremony and for gazing into other worlds.
• During the gold rushes, miners mistook its brassy glint for the real thing and called it Fool's Gold, a name that stuck long after the disappointment faded.