Judging quality
Danburite looks like topaz but has no easy cleavage and a distinctly wedge-shaped termination. Mexican crystals often show a faint pink core.
Silicate
Danburite
Chisel-tipped prisms of glassy calcium boron silicate, most familiar from the Charcas mines of San Luis Potosí where crystals grow water-clear and doubly terminated.
Care
Hard and stable; wash with water. Terminations chip if knocked.
History & lore
Named for Danbury, Connecticut, where it was first found in 1839 — the type locality is now built over.
Cultural history, recorded as tradition rather than as medical or scientific claim.
Common questions about Danburite
- What is Danburite?
- Chisel-tipped prisms of glassy calcium boron silicate, most familiar from the Charcas mines of San Luis Potosí where crystals grow water-clear and doubly terminated.
- How hard is Danburite and what is it made of?
- Danburite is a Silicate-family mineral with the composition CaB2Si2O8. It crystallizes in the orthorhombic system and rates 7-7.5 on the Mohs hardness scale. It occurs in colorless, pale yellow, blush.
- Where does Danburite come from?
- Notable localities for Danburite include Charcas, Mexico, Madagascar, Myanmar, Japan.
- How do you tell good Danburite from filler?
- Danburite looks like topaz but has no easy cleavage and a distinctly wedge-shaped termination. Mexican crystals often show a faint pink core.
- How do you care for Danburite?
- Hard and stable; wash with water. Terminations chip if knocked.
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.