smoky quartz

Also known as cairngorm

quartz variety

In the Vinony graph

Within Vinony's link graph, smoky quartz is referenced by 264 other articles, and connects out to hexagonal crystal system, jewelry and China.

It is catalogued under topics including Commons link from Wikidata, Quartz gemstones and Quartz varieties.

Its subject is documented across 35 Wikipedia language editions.

Key facts

Category: Tectosilicate minerals
Group: Quartz group
Formula: SiO 2
Ima status: Variety of quartz
Strunz classification: 04.DA.05
Dana classification: 75.01.03.01
Crystal system: α-quartz: trigonal trapezohedral class 3 2 , β-quartz: hexagonal 622
Space group: Trigonal 32
Unit cell: a = 4.9133 Å , c = 5.4053 Å; Z=3
Colour: Brown, gray, black
Crystal habit: 6-sided prism ending in 6-sided pyramid (typical), drusy, fine-grained to microcrystalline, massive
Twinning: Common Dauphine law, Brazil law and Japan law
Cleavage: {0110} none
Fracture: Conchoidal
Tenacity: Brittle
Mohs scale hardness: 7 – lower in impure varieties (defining mineral)
Luster: Vitreous – waxy to dull when massive
Streak: White

via Wikipedia infobox

Wikidata facts

Subclass of: quartz
Image: USDA Mineral Smokey Quartz 93v3949.jpg

Show 7 more facts

described by source: Mala hirnycha encyclopædia
Commons category: Smoky quartz
Commons gallery: Smoky quartz
Mohs' hardness: 7
streak color: white
density: 2.585
chemical formula: SiO₂

Sources (3)

via Wikidata · CC0

~2 min read

Encyclopedic overview

Smoky quartz is a brown to black, translucent variety of quartz. It ranges in clarity from almost complete transparency to almost-opaque black crystals. Smoky quartz is popular as a gemstone and as a collectible crystal.

Properties

Excerpted from Wikipedia’s “smoky quartz” article, available under the CC BY-SA 4.0 licence.