Image: <bdi><a href="https://www.wikidata.org/wiki/Q108103612" class="extiw" title="d:Q108103612"><span title="Wikipedian and OpenStreetMap mapper from Cologne, Open Data activist">Raimond Spekking</span></a></bdi> (CC BY-SA 4.0)
hexagonalrareSilicates (Feldspathoid, Cancrinite group)
Afghanite
(Na,K)₂₂Ca₁₀(Si₂O₆)₆(SO₄)₆Cl₆·H₂O
This specimen features deep blue Afghanite crystals, likely intergrown or massive, contrasting with metallic yellow Pyrite. The Afghanite exhibits a vibrant blue hue typical of the mineral.
Afghanite Physical Properties
Mohs Hardness
5.5Crystal System
hexagonalLuster
vitreousStreak Color
whiteCleavage
imperfect on {1010}Fracture
conchoidalSpecific Gravity
2.6Colors
blue, colorless, white, gray, greenTransparency
transparentType Locality
Sar-e-Sang, Badakhshan Province, Afghanistan (type locality); Gjaidtroghöhe, Großes Fließtal, Austria (specimen locality)Mineral Group
Silicates (Feldspathoid, Cancrinite group)Uses
collector, gemstone (rarely)Associated Minerals
pyrite, lazurite, diopside, calcite, dolomiteRarity
rareGeological Context
Afghanite typically forms in contact metamorphic rocks, particularly in calc-silicate skarns or marbles, often associated with lazurite deposits. It is a product of metasomatic alteration.
