Smoky Quartz

Add one script tag to your page:

<div data-gemfyi="entity" data-slug="smoky-quartz"></div>
<script src="https://cdn.jsdelivr.net/npm/gemfyi-embed@1/dist/embed.min.js" defer></script>

Embed as an iframe:

<iframe src="https://gemfyi.com/iframe/entity/smoky-quartz/?style=modern&theme=light" width="420" height="400" frameborder="0" loading="lazy" style="border:0;border-radius:10px;max-width:100%"></iframe>

Paste the URL in WordPress, Medium, or Ghost:

https://gemfyi.com/ja/gems/smoky-quartz/

Shields.io-compatible SVG badge:

![Smoky Quartz](https://gemfyi.com/badge/entity/smoky-quartz.svg)

Web Component:

<gemfyi-entity slug="smoky-quartz"></gemfyi-entity>
<script src="https://cdn.jsdelivr.net/npm/gemfyi-embed@1/dist/embed.min.js" defer></script>

Smoky quartz is the translucent to transparent brownish-gray to nearly black variety of quartz, its color produced by natural irradiation of aluminum-bearing crystals within the Earth's crust over millions of years. It is the national gemstone of Scotland, where it has featured in Celtic jewelry and Highland dress since antiquity, and it occurs worldwide in granitic rocks and pegmatites, with particularly large crystals from Brazil and the Swiss Alps. A Mohs hardness of 7 and good clarity make it both durable and affordable, and it is readily faceted into large, clean stones as well as carved ornaments. Crystallizing in the trigonal system with a refractive index near 1.544, it shares the optical constants of all quartz, and gentle heating can lighten or remove its smoky tone.

Physical & Optical Properties

Category Semi-Precious Gems

Mohs Hardness 7.0

Specific Gravity 2.65

Refractive Index 1.544 – 1.553

Crystal System Trigonal

Cleavage None

Fracture Conchoidal

Color various

Birefringence 0.009

Dispersion 0.013

Pleochroism Dark: definite - brown, reddish-brown

Mohs Hardness

Mohs hardness of Smoky Quartz shown against the ten reference minerals, from talc (1) to diamond (10).

Mohs	Reference mineral	Smoky Quartz
1	Talc
2	Gypsum
3	Calcite
4	Fluorite
5	Apatite
6	Orthoclase
7	Quartz	●
8	Topaz
9	Corundum
10	Diamond

Crystal System

Value & Market

Price Tier Moderate ($50-500/ct)

Where to Buy Smoky Quartz

Blue Nile Fine jewelry retailer

James Allen Gemstone jewelry

Brilliant Earth Ethically sourced gems

Amazon Wide selection

Links may earn a commission at no extra cost to you.

Treatments

May be produced by irradiation of rock crystal (not detectable with standard tests) - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 7 7Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) 2.65Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) BrittleWalter Schumann, Gemstones of the world (2001) Very brittle NoneWalter Schumann, Gemstones of the world (2001) ConchoidalWalter Schumann, Gemstones of the world (2001) 1.544 to 1.553Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) Uniaxial/+Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) 0.009Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) Dark: definite - brown, reddish-brownWalter Schumann, Gemstones of the world (2001) More from other references 0.013Walter Schumann, Gemstones of the world (2001) Clear brown colour and varying from a light brown to dark a brownMichael O?Donoghue, Gems, Sixth Edition (2006) Smokey, color center related to the Al3+ impurity.W. William Hanneman, Pragmatic Spectroscopy For Gemologists (2011) Transparent,Translucent,OpaqueUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) Usually noneWalter Schumann, Gemstones of the world (2001) TrigonalUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) Hexagonal prismsWalter Schumann, Gemstones of the world (2001) Smoky Quartz information at mindat.org Bolivia  Laurs (2001, 2010) Laurs (2001, 2010) Brazil  Macri et al. (2006) Macri et al. (2006) Kenya  Madagascar  Madagascar, extraLapis English No.1, 2001, p. 46 Pezzotta (2001) Madagascar, extraLapis English No.1, 2001, p. 43 Danet (2009) Mozambique  Bettencourt-Dias and Wilson (2000) Myanmar  Ted Themelis (2008) Gems & mines of Mogok Ted Themelis (2008) Gems & mines of Mogok Sri Lanka  UK  No reference listed USA 

About Smoky Quartz

スモーキークォーツは透明から半透明の褐色灰色からほぼ黒色の石英変種で、その色は地中のアルミニウムを含む結晶への数百万年にわたる自然放射線の照射によって生じます。スコットランドの国石であり、古くからケルトの宝飾品やハイランドドレスのアクセサリーに使用されています。世界中の花崗岩質岩とペグマタイトに産出し、特にブラジルとスイスアルプスからは大型の結晶が知られています。