Minerals & Gemstone 480x104

Advertising Information

Translucent Bright Blue Afghanite

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
Composition Hydrous silicate of sodium, calcium, and potassium, with chloride, carbonate, and sulfate radicals
Color Light to dark blue. Microcrystals from Italy may be be white, colorless, or light yellow.
Streak White
Hardness 5.5 - 6
Crystal System Hexagonal
Crystal Forms
and Aggregates
In wide or elongated prismatic crystals with partial or stepped pyramidal terminations. Occasionally doubly terminated as bypyramidal crystals. Also as distorted crystal groups, as tabular microcrystals, grainy, and encrusting.
Transparency Translucent to Opaque
Specific Gravity 2.5 - 2.6
Luster Vitreous
Cleavage 1, All
Fracture Conchoidal to uneven
Tenacity Brittle
Other ID Marks Often fluorescent yellow to orange in longwave ultraviolet light.
In Group Silicates; Tectosilicates; Feldspathoid Group
Striking Features Color, crystal habit, and locality
Environment In Lazurite veins in metamorphosed limestones.
Rock Type Metamorphic
Popularity (1-4) 3
Prevalence (1-3) 3
Demand (1-3) 2

Afghanite AUCTIONS

Afghanite is strictly used as a rare collectors mineral.

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.

Calcite, Lazurite, Pyrite, Diopside, Muscovite, Forsterite

Lazurite - Forms in different crystals; has blue streak and poor cleavage.

afghanite PHOTOS
DISCUSSIONView Forum | Post to Forum
Have a question about Afghanite? Visit our Q&A Community and ask the experts!

To sponsor this page, click here.

Let us know how we can update this page
(Click for more details)
We strive for accurate content and locality information. If you feel any of the content is incorrect, or if you feel we are missing vital locality information, please fill out the form below so we can update the site. If you are requesting a locality be added, please only include significant locality occurences for the mineral.