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 (Tectosilicates, Feldspar Group, Plagioclase Series)
Andesine
(Na,Ca)Al(Si,Al)3O8
This specimen features a reddish-orange, somewhat blocky crystal of andesine, possibly displaying some cleavage faces, embedded within a darker matrix.
Andesine Physical Properties
Mohs Hardness
6Crystal System
triclinicLuster
vitreousStreak Color
whiteCleavage
perfect on {001} and {010}, intersecting at nearly 90 degreesFracture
unevenSpecific Gravity
2.67Colors
white, gray, reddish, green, yellowTransparency
transparentType Locality
Silberberg Mine, Bodenmais, Lower Bavaria, Bavaria, GermanyMineral Group
Silicates (Tectosilicates, Feldspar Group, Plagioclase Series)Uses
gemstone, collectorAssociated Minerals
quartz, cordierite, garnet, other feldsparsRarity
uncommonGeological Context
Andesine is a common rock-forming mineral found in intermediate igneous rocks like diorite and andesite, and in some metamorphic rocks. This specific specimen comes from a polymetamorphic iron sulphide deposit hosted in cordierite-garnet gneiss, disseminated by quartz veins.
