Image: <bdi><a href="https://www.wikidata.org/wiki/Q56247090" class="extiw" title="d:Q56247090"><span title="mineral collector and dealer">Robert M. Lavinsky</span></a></bdi> (CC BY-SA 3.0)
triclinicuncommonSilicates
Bytownite
(Ca,Na)(Al,Si)AlSi2O8
This specimen shows a blocky, light-colored crystal of bytownite, likely white or gray, exhibiting good cleavage and a vitreous luster. It appears somewhat translucent.
Bytownite Physical Properties
Mohs Hardness
6Crystal System
triclinicLuster
vitreousStreak Color
whiteCleavage
Perfect on {001} and {010}, good on {110}Fracture
unevenSpecific Gravity
2.73Colors
white, gray, yellowish, greenish, brownishTransparency
transparentType Locality
Dorado Mine, Casas Grandes, Chihuahua, MexicoMineral Group
SilicatesUses
collector, scientific-studyAssociated Minerals
olivine, pyroxene, amphibole, magnetiteRarity
uncommonGeological Context
Bytownite is a calcium-rich plagioclase feldspar that forms in high-temperature mafic igneous rocks like gabbro and basalt, and occasionally in high-grade metamorphic rocks. It is a primary rock-forming mineral in these environments.
