Judging quality
Natural iridescence is subtler and patchier than the uniform electric rainbow of treated material. Sharp tetrahedral crystals in matrix are the collector form.
Sulfide
Chalcopyrite (Peacock Ore)
Copper iron sulfide whose tarnish film refracts into peacock blues, purples and greens. Most 'peacock ore' sold has been acid-treated to intensify the effect.
Care
Tarnish continues to develop. Handle minimally; do not wash treated pieces, as the color film is superficial.
History & lore
Chalcopyrite is the single most important copper ore mineral in the world.
Cultural history, recorded as tradition rather than as medical or scientific claim.
Common questions about Chalcopyrite (Peacock Ore)
- What is Chalcopyrite (Peacock Ore)?
- Copper iron sulfide whose tarnish film refracts into peacock blues, purples and greens. Most 'peacock ore' sold has been acid-treated to intensify the effect.
- How hard is Chalcopyrite (Peacock Ore) and what is it made of?
- Chalcopyrite (Peacock Ore) is a Sulfide-family mineral with the composition CuFeS2. It crystallizes in the tetragonal system and rates 3.5-4 on the Mohs hardness scale. It occurs in gold, iridescent.
- Where does Chalcopyrite (Peacock Ore) come from?
- Notable localities for Chalcopyrite (Peacock Ore) include Mexico, Peru, USA (Tennessee), Spain.
- How do you tell good Chalcopyrite (Peacock Ore) from filler?
- Natural iridescence is subtler and patchier than the uniform electric rainbow of treated material. Sharp tetrahedral crystals in matrix are the collector form.
- How do you care for Chalcopyrite (Peacock Ore)?
- Tarnish continues to develop. Handle minimally; do not wash treated pieces, as the color film is superficial.
See it in person
Photographs only go so far
Both rooms are open six days a week, and there is always someone happy to pull pieces out of the case so you can compare them under the light.