Mineral · Feldspar group
Microcline
K(AlSi3O8)
Microcline is the triclinic potassium feldspar; its blue-green variety amazonite (coloured by lead and water) with smoky quartz from the Pikes Peak batholith of Colorado is one of the most iconic American mineral combinations, also found at Konso (Ethiopia), Russia and Virginia. Crystals are blocky and the colour is unmistakable. Amazonite is also sold tumbled and carved from Russia and Brazil.
| Formula | K(AlSi3O8) |
|---|---|
| IMA status | grandfathered |
| Crystal system | Triclinic |
| Mohs hardness | 6–6.5 |
| Group | Feldspar group |
| Type locality | None |
| Streak | White |
| Specific gravity | 2.56 |
| Reference list | IMA List of Minerals (RRUFF) — verify formula and status against the current list |
Fakes and treatments
Pikes Peak amazonite-and-smoky groups are sometimes reassembled from loose crystals after digging; ask whether the plate is a natural pocket or a 'repair'.
Elsewhere
Cite this article
Stratum Study. "Microcline" (Mineral). Stratum Study pack 2026.09, as of 2026-09-19. https://stratum.black/study/minerals/microcline. Accessed 2026-09-20.
@misc{stratum-microcline,
title = {Microcline},
author = {{Stratum Study}},
howpublished = {\url{https://stratum.black/study/minerals/microcline}},
year = {2026},
note = {Mineral article, Stratum Study pack 2026.09, as of 2026-09-19; sources: stratum, wikidata, commons. Accessed 2026-09-20.}
} 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.