Judging quality
Heavy for its size with a resinous lustre. Nearly identical to pyromorphite in habit — mimetite trends yellow-orange, pyromorphite green.
Arsenate
Mimetite
Lead arsenate that grows as glassy yellow barrel crystals or as botryoidal 'campylite' spheres. The Mexican Mapimí material, in warm marigold rounds, is the one most often seen.
Care
Lead and arsenic bearing. Dry handling, wash hands, no ultrasonics.
History & lore
The name is from the Greek mimetes, imitator, for the resemblance to pyromorphite.
Cultural history, recorded as tradition rather than as medical or scientific claim.
Common questions about Mimetite
- What is Mimetite?
- Lead arsenate that grows as glassy yellow barrel crystals or as botryoidal 'campylite' spheres. The Mexican Mapimí material, in warm marigold rounds, is the one most often seen.
- How hard is Mimetite and what is it made of?
- Mimetite is a Arsenate-family mineral with the composition Pb5(AsO4)3Cl. It crystallizes in the hexagonal system and rates 3.5-4 on the Mohs hardness scale. It occurs in yellow, orange, green.
- Where does Mimetite come from?
- Notable localities for Mimetite include Mapimí, Mexico, Tsumeb, Namibia, Cumbria, England, Poland.
- How do you tell good Mimetite from filler?
- Heavy for its size with a resinous lustre. Nearly identical to pyromorphite in habit — mimetite trends yellow-orange, pyromorphite green.
- How do you care for Mimetite?
- Lead and arsenic bearing. Dry handling, wash hands, no ultrasonics.
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.