Mineral · Tectosilicates
Danburite
CaB2Si2O8
Danburite is calcium borosilicate, forming colourless to pale pink prisms with a chisel-shaped termination that resemble topaz, from Charcas (San Luis Potosí, Mexico), Myanmar and Madagascar. Charcas danburite clusters are inexpensive and clean. It lacks topaz's basal cleavage, which is the quickest way to tell them apart.
| Formula | CaB2Si2O8 |
|---|---|
| IMA status | grandfathered |
| Crystal system | Orthorhombic |
| Mohs hardness | 7–7.5 |
| Group | Tectosilicates |
| Type locality | Danbury, Connecticut, USA |
| Streak | White |
| Specific gravity | 3.0 |
| Reference list | IMA List of Minerals (RRUFF) — verify formula and status against the current list |
Elsewhere
Cite this article
Stratum Strata. "Danburite" (Mineral). Stratum Strata pack 2026.09, as of 2026-09-21. https://stratum.black/strata/minerals/danburite. Accessed 2026-09-21.
@misc{stratum-danburite,
title = {Danburite},
author = {{Stratum Strata}},
howpublished = {\url{https://stratum.black/strata/minerals/danburite}},
year = {2026},
note = {Mineral article, Stratum Strata pack 2026.09, as of 2026-09-21; sources: stratum, wikidata, commons. Accessed 2026-09-21.}
} Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.