silicates
Danburite
CaB2Si2O8
- Crystal system
- orthorhombic
- Hardness
- 7–7.5 on the Mohs scale
- Lustre
- vitreous
- Colour
- Colourless, pale yellow, pink
- Where it forms
- In contact metamorphic zones and in hydrothermal veins, often with boron minerals.
- Chiefly from
- Charcas, MexicoDalnegorsk, RussiaMyanmarMadagascar
Why it is that colour
Usually colourless; impurities give faint tints.
Safety
Safe to handle.
Where it comes from
Mexican material from Charcas and Russian material from Dalnegorsk supply most specimens. Faceted danburite is uncommon and mostly a collector’s stone.
Historical use
A minor boron mineral of no economic significance.
Recorded as history and attributed where possible. That a stone was used for something establishes that people used it, not that it worked.
What is attributed to it, and since when
Named in 1839 after Danbury, Connecticut, where it was first found — the original locality is now built over. No traditional attribution.
Described, not endorsed. Dating a claim is not the same as assessing it — but an association that first appears in a book published in 1985 is not an ancient inheritance, whatever the label says. A sincere account of feeling better is compatible with the stone doing nothing — see the placebo effect.
Worth knowing
Danburite is a good example of a stone whose crystal-trade reputation is built almost entirely on appearance. It is colourless, glassy, hard and well formed, and it acquired a set of meanings around clarity and higher awareness that map straightforwardly onto looking clear.
Mineralogically it is a calcium borosilicate with a structure related to feldspar, from a town in Connecticut that no longer has any.
Identity checked against IMA-CNMNC master list, June 2025.