The Mineral afghanite
Afghanite is a rare and coveted mineral with a striking blue color, first identified in 1968. With a very close resemblance to Lazurite, and occurring together in the same deposits, Afghanite is distinguished by its unique crystal habit. Afghanite is named after its most significant locality in northern Afghanistan.
Chemical Formula
(Na,Ca,K)8Al6Si6O24(Cl2,SO4,CO3)3 · 0.5H2O
Color
Light to dark blue. Microcrystals from Italy may be be white, colorless, or light yellow.
Uses
Afghanite is strictly used as a rare collectors mineral.
Noteworthy Localities
Afghanite is a rare mineral, with the only significantly important deposit being Sar-e Sang, Kokcha Valley, in Badakshan Province,
Afghanistan, where it forms large and beautiful crystals that are almost always embedded on a white marble matrix. Small crusts of Afghanite occur in the vicinity of Slyudyanka, near the southern area of Lake Baikal, and white and colorless microcrystals in the vicinity of Vico Lake, near Viterbo, Italy.
Distingushing Similar Minerals
Lazurite - Forms in different crystals; has blue streak and poor cleavage.