About Quartz

SiO₂

One of the most abundant minerals of the Earth's crust, quartz is the pure silica framework mineral and occurs as colorless prismatic crystals as well as in a wide range of colored varieties. It is piezoelectric and has a Mohs hardness of 7, which makes it a reference point on the hardness scale.

Show 65 localities on the map

Photos of Quartz

**Smoky quartz** · Florissant area (Teller County)
Cabinet-size smoky quartz crystals on green amazonite (specimen from Florissant area, Teller County, Colorado, USA).
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source

**Smoky quartz** · Graubünden
Twisted smoky quartz crystal (gwindel) with a serrated edge (specimen from Graubünden, Switzerland).
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source

**Smoky quartz** · Goboboseb Mountains
Solid smoky quartz specimen with sceptred, hoppered skeletal growth.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source

**Amethyst** · Goboboseb Mountains
Amethyst crystals up to 4.5 cm in a calcite-lined cavity on matrix.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source

**Amethyst** · Piedra Parada (Tatatila)
Amethyst crystals lying across a rounded matrix, many with both ends developed, from Piedra Parada, Veracruz, Mexico.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source

**Amethyst** · Amatitlan amethyst veins (Eduardo Neri)
Small cluster of amethyst crystals with colour zoning, about 5 cm, from Amatitlan, Guerrero, Mexico.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source

**Smoky quartz** · Val Giuv (Tujetsch)
Lustrous pair of smoky quartz crystals, labelled Giuv Valley.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source

**Amethyst** · Diamond Willow Mine (Pearl Station)
Cabinet specimen of glassy purple amethyst crystals, the largest 3.1 cm across, from the Diamond Willow Mine near Pearl, Ontario.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source

Where Quartz is found (65)

Afghanistan

Darra-i-Pech pegmatite fieldNangarhar · 1 photo

Argentina

PapachacraCatamarca · 3 photos

Bolivia

Anahi MineSanta Cruz · 6 photos
Siglo Veinte MinePotosi

Brazil

Ametista do SulRio Grande do Sul
AraçuaíMinas Gerais · 3 photos
Berilo Branco claimMinas Gerais · 3 photos
Conselheiro PenaMinas Gerais
GalileiaMinas Gerais
Ilha claim (Lavra da Ilha)Minas Gerais · 3 photos
Junco do SeridoParaiba
Minas GeraisMinas Gerais · 1 photo
Serra dos CristaisGoiás

Bulgaria

Madan ore fieldSmolyan Province

Canada

Diamond Willow Mine (Pearl Station)Ontario · 3 photos
Rose Quartz Pit (Quadeville West Mine / Rose Quartz Quarry)Ontario
Thunder Bay Amethyst Panorama (Amethyst Mine)Ontario

China

Qinglong hills (Qinglongshan), DonghaiJiangsu
Yaogangxian MineHunan

France

La Gardette mineIsère

Greenland

IgalikuKujalleq

Hungary

Gyöngyösoroszi (Altáró)Heves County

Italy

Capurru Quarry (Osilo)Sardinia · 3 photos
Torano quarriesTuscany

Kosovo

Trepca complexMitrovica District

Madagascar

Antoby QuarryAmoron'i Mania
Madagascar · 1 photo
Vohibola pegmatites (Mangarano, Antsirabe II)Vakinankaratra

Mexico

Amatitlan amethyst veins (Eduardo Neri)Guerrero · 3 photos
CharcasSan Luis Potosí · 3 photos
NaicaChihuahua
Piedra Parada (Tatatila)Veracruz · 3 photos

Namibia

Erongo MountainErongo · 3 photos
Goboboseb MountainsErongo · 10 photos
Tsumeb MineOshikoto Region

Peru

HuanzalaAncash

Romania

CavnicMaramures County

Russia

Bor Pit (Dal'negorsk B deposit)Primorsky Krai · 3 photos

South Africa

Boekenhoutshoek (Boekenhouthoek)Mpumalanga · 3 photos

Spain

VillasbuenasSalamanca

Switzerland

Gletschhorn smoky quartz cleftUri
GraubündenGraubünden · 4 photos
Göschenen ValleyUri · 3 photos
PlanggenstockUri
St Gotthard pass area (Central St Gotthard Massif)Ticino · 3 photos
Val Giuv (Tujetsch)Graubünden · 3 photos

United Kingdom

Loch Avon (Beinn Mheadhoin and eastern crags)Scotland

United States

Conway (Redstone area), Carroll CountyNew Hampshire · 3 photos
Dunton Gem QuarryMaine
East Coleman MineArkansas · 2 photos
Esmeralda MineCalifornia · 3 photos
Florissant area (Teller County)Colorado · 4 photos
Four Peaks Amethyst MineArizona · 1 photo
Hiddenite (Alexander County)North Carolina · 2 photos
Jackson Crossroads Amethyst MineGeorgia · 3 photos
Joplin FieldMissouri
Little Three MineCalifornia · 3 photos
Middleville (Herkimer County)New York · 1 photo
Middleville (Herkimer diamond district)New York
Mount Mica QuarryMaine · 2 photos
Pink Panther MineSouth Dakota
Smoky Hawk claimColorado · 2 photos
Wegner Quartz Crystal MinesArkansas

Uruguay

Los Catalanes Gemological DistrictArtigas · 3 photos

Zambia

MapatizyaSouthern Province

Quartz on the same specimen with other minerals

Same specimen Marcasite growing on Quartz at Joplin Field

The same Joplin description lists quartz among the surfaces on which the bladed marcasite crystals sit, next to galena, sphalerite, calcite, chert and jasperoid.

Glittering marcasite on clear or milky quartz is a sought-after contrast of sulfide and silicate.

Sources: SRC-015

Same specimen Marcasite intergrown with Quartz at Siglo Veinte Mine

A Siglo XX specimen from the Contacto vein carries sharp, water-clear prismatic quartz crystals with small golden marcasite clusters (to about 6 mm) on the same piece, together with a tan siderite coating.

Clear quartz prisms set off by golden sulfide clusters from a classic Bolivian tin-district locality.

Sources: SRC-154

Same specimen Pyrite growing on Quartz at Huanzala

Huanzala specimens show sharp, lustrous octahedral pyrite crystals (to about 2 cm) on the face of a crystallized quartz matrix; other pieces show glassy quartz crystals with pyrite scattered through them.

Bright golden pyrite against glassy quartz is one of the best-known Peruvian combination pieces.

Sources: SRC-155 SRC-156

Same specimen Galena growing on Quartz at Madan ore field

Cabinet specimens from Madan show lustrous silver-grey galena crystals, many with skeletal or hopper-like modified cube forms and some spinel-twinned, on a matrix of needle-like quartz, with chalcopyrite also present.

The skeletal galena habit is typical of Madan, and the needle quartz base makes a dramatic, delicate display.

Sources: SRC-157

Same specimen Amethyst growing on Galena at Naica

A Naica specimen shows gemmy purple amethyst crystals to about 3 cm rising from a bed of bright metallic galena crystals.

Deep purple amethyst on a shiny lead-grey base is a striking and unusual colour pairing.

Sources: SRC-158 SRC-159

Same specimen Amethyst growing on Pyrite at Cavnic

A large Cavnic specimen carries pastel purple, lightly frosted amethyst clusters to about 5 cm on a plate covered with brass-yellow striated pyrite crystals.

Amethyst of this size is described as rare from the Cavnic mines, and the golden pyrite base adds contrast.

Sources: SRC-160 SRC-161

Same specimen Amethyst growing on Chalcopyrite at Cavnic

On the same type of Cavnic plate, iridescent brassy chalcopyrite crystals occur on the matrix together with the pyrite, and the amethyst clusters rise from this sulfide-covered matrix.

The iridescent chalcopyrite adds a second metallic colour beneath the purple quartz.

Sources: SRC-160 SRC-161

Same specimen Chalcopyrite growing on Quartz at Yaogangxian Mine

A Yaogangxian specimen has a floret of sharp golden chalcopyrite sphenoids, about 3 cm, set on a tabular doubly terminated quartz crystal; contacts are healed and overgrown by quartz faces.

Iridescent chalcopyrite on a glassy, doubly terminated quartz is a rare and aesthetic floater-type piece.

Sources: SRC-162

Same specimen Pyrite included in Quartz at Middleville (Herkimer diamond district)

Herkimer-type quartz crystals commonly contain small inclusions of minerals, including pyrite, alongside calcite, dolomite and sphalerite.

Inclusions inside the clear, doubly terminated crystals add interest and are prized in Herkimer quartz.

Sources: SRC-139

Same specimen Quartz intergrown with Galena at Trepca complex

Trepca specimens are shown that consist mainly of galena with slender quartz prisms, some with a small cluster of quartz prisms; the captions do not say which mineral grew first.

Slender quartz prisms combined with galena illustrate the sulfide and quartz vein assemblage of this famous ore belt.

Sources: SRC-061

Same specimen Quartz intergrown with Galena at Tsumeb Mine

A Tsumeb collection specimen of octahedral galena crystals (to 9 mm) occurs together with quartz and minor dolomite.

Sharp galena octahedra on a Tsumeb specimen carry the prestige of this classic African locality.

Sources: SRC-045

Same specimen Quartz with Marcasite at Cavnic

1 specimen photo(s) from this locality show marcasite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Chalcopyrite at Cavnic

1 specimen photo(s) from this locality show chalcopyrite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Chalcopyrite at Animón Mine (Huarón mining district)

2 specimen photo(s) from this locality show chalcopyrite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Chalcopyrite at Huarón Mine (Huarón Mining District)

Same specimen Quartz with Chalcopyrite at Ellenville Mine (Ellenville Lead Mine; Ulster mine)

Same specimen Quartz with Galena at Krushev dol Mine

1 specimen photo(s) from this locality show galena with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Galena at Neudorf (Harzgerode)

1 specimen photo(s) from this locality show galena with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Vanadinite at Los Lamentos Mountains (Ahumada mine area)

1 specimen photo(s) from this locality show vanadinite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Sphalerite at Bachelor Mine (Amethyst vein, Creede)

2 specimen photo(s) from this locality show sphalerite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Sphalerite at Krushev dol Mine

1 specimen photo(s) from this locality show sphalerite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Sphalerite at Camp Bird Mine

Same specimen Quartz with Pyrite at Huarón Mine (Huarón Mining District)

1 specimen photo(s) from this locality show pyrite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Hematite with Quartz at Diamond Willow Mine (Pearl Station)

2 specimen photo(s) from this locality show quartz with hematite together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Hematite with Quartz at Göschenen Valley

1 specimen photo(s) from this locality show quartz with hematite together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Albite with Quartz at Papachacra

1 specimen photo(s) from this locality show quartz with albite together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Albite with Quartz at Little Three Mine

2 specimen photo(s) from this locality show quartz with albite together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Microcline with Quartz at Conway (Redstone area), Carroll County

1 specimen photo(s) from this locality show quartz with microcline together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Albite with Quartz at Conway (Redstone area), Carroll County

1 specimen photo(s) from this locality show quartz with albite together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Microcline with Quartz at Florissant area (Teller County)

Same specimen Microcline with Quartz at Smoky Hawk claim

Same specimen Albite with Quartz at Berilo Branco claim

1 specimen photo(s) from this locality show quartz with albite together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Dolomite at Serra das Eguas (Brumado)

1 specimen photo(s) from this locality show dolomite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Dolomite at Morro Velho Mine (Nova Lima)

Same specimen Quartz with Dolomite at Banska Stiavnica

2 specimen photo(s) from this locality show dolomite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Microcline at Konso

1 specimen photo(s) from this locality show microcline with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Microcline at Lake George (Park County)

Same specimen Quartz with Microcline at Pikes Peak

Same specimen Quartz with Microcline at Crystal Peak (Teller County)

Same specimen Quartz with Microcline at Papachacra

Same specimen Quartz with Microcline at Smoky Hawk claim

2 specimen photo(s) from this locality show microcline with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Microcline at Florissant area (Teller County)

Same specimen Quartz with Microcline at Himalaya Mine

Same specimen Quartz with Microcline at Erongo Mountain

Same specimen Quartz with Siderite at Neudorf (Harzgerode)

3 specimen photo(s) from this locality show siderite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Siderite at Santa Eulalia Mining District

1 specimen photo(s) from this locality show siderite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Siderite at Allevard

Same specimen Quartz with Siderite at Camborne-Redruth-St Day District

Same specimen Quartz with Siderite at Georg Mine (Willroth)

Same specimen Quartz with Pyrrhotite at Nikolaevskiy Mine

2 specimen photo(s) from this locality show pyrrhotite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Pyrrhotite at Dalnegorsk

Same specimen Quartz with Pyrrhotite at Morro Velho Mine

1 specimen photo(s) from this locality show pyrrhotite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Enargite at Butte Mining District

1 specimen photo(s) from this locality show enargite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Enargite at Leonard Mine

Same specimen Quartz with Bornite at Dzhezkazgan Mine (Zhezkazgan)

2 specimen photo(s) from this locality show bornite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Bornite at Carn Brea Mine

1 specimen photo(s) from this locality show bornite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Bornite at Butte Mining District

1 specimen photo(s) from this locality show bornite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Bornite at Leonard Mine

2 specimen photo(s) from this locality show bornite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Beryl at Shigar Valley

1 specimen photo(s) from this locality show beryl with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Beryl at Cryo-Genie Mine (Lost Valley Truck Trail Mine)

1 specimen photo(s) from this locality show beryl with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Rhodochrosite at Cavnic

3 specimen photo(s) from this locality show rhodochrosite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Rhodochrosite at Butte Mining District

1 specimen photo(s) from this locality show rhodochrosite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Rhodochrosite at Taxco de Alarcón

Same specimen Quartz with Rhodochrosite at Pachapaqui Mining District

2 specimen photo(s) from this locality show rhodochrosite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Rhodochrosite at Pasto Bueno District (Huayllapon Mine)

Same specimen Quartz with Rhodochrosite at Starnitsa deposit (Davidkovo ore field)

Same specimen Quartz with Rhodochrosite at Grizzly Bear Mine (Bear Creek, Ouray)

Same specimen Quartz with Rhodochrosite at Madan ore field

Same specimen Quartz with Rhodochrosite at Climax Mine

Identity

Varieties: Amethyst, Citrine, Smoky quartz, Rock crystal, Rose quartz
Strunz: 4.DA.05 · 4 Oxides and hydroxides
IMA status: Grandfathered
Name origin: The word is German in origin and may derive from a miners' term for a cross-vein ore; the older Greek word kristallos (ice) is the root of the term 'crystal' and of the historical name for clear quartz. The Handbook notes the name was first applied to gangue in Saxony.
Elements: Si, O

Physical properties

Color: Colorless or white when pure; inclusions and impurities give rose-pink, yellow to brown, green, blue, violet, brown or black; often zoned or mottled
Streak: White
Luster: Vitreous luster
Transparency: Variable
Mohs hardness: 7
Density: 2.65–2.66 g/cm³
Cleavage / fracture: Cleavage rarely observable (poor on rhombohedral and prism planes); rhombohedral parting; fracture conchoidal; brittle, tough when massive
Magnetism / fluorescence: Piezoelectric and pyroelectric; may show triboluminescence

Crystallography

Crystal system: Trigonal
Space group: P3₁ 21 or P3₂ 21
Structure: Three-dimensional framework of corner-sharing SiO4 tetrahedra; unit cell a = 4.9135 Å, c = 5.4050 Å, Z = 3. Low (alpha) quartz is stable below 573 °C at 1 bar.
Typical habit: Six-sided prisms with striations across the prism faces, topped by rhombohedral terminations; also stubby, needle-like, pseudocubic, in parallel or divergent groups, drusy, and microcrystalline to massive
Twinning: Very common: Dauphiné law (penetration twin), Brazil law (contact twin) and Japan law (contact twin on an inclined axis)
Optical data: Uniaxial (+); refractive indices omega = 1.544, epsilon = 1.553

Formation and use

Formation: Crystallizes from silica-rich fluids in hydrothermal veins and cavities (epithermal to Alpine-type), in granites and pegmatites, and late in igneous crystallization, typically at roughly 150-600 °C. Also forms in sandstones and quartzites, as authigenic crystals in carbonate rocks, and as a residual mineral in soils and sediments.
Uses: Raw material for silicon, glass-making, frequency standards and optical instruments, concrete and filtration sand; gem and ornamental material; collector specimens.
Stability and care: Converts to beta-quartz at 573 °C (1 bar). Crystals rich in fluid or gas inclusions may crack on heating, so only gentle warming (for example warm water) is advisable. Color in smoky, amethyst and similar varieties comes from radiation-induced color centers that heat can destroy; rose quartz fades quickly in strong light, and the other colored varieties fade more slowly.

Related minerals

Related minerals: Chalcedony (microcrystalline quartz)
Polymorphs: Cristobalitetridymitecoesitestishovite
Can be confused with: Cordieritenepheline

Sources

SRC-084 · Book
Handbook of Mineralogy - QuartzAnthony, J.W.; Bideaux, R.A.; Bladh, K.W.; Nichols, M.C. · 2001 · Mineralogical Society of America / Mineral Data Publishing
SRC-085 · Database
Quartz (Mindat.org mineral page)Mindat.org / Hudson Institute of Mineralogy
SRC-088 · Database
Wegner Quartz Crystal Mines, Mt Ida, Montgomery County, Arkansas, USAMindat.org

Draft data from the Provenite workbook. Check entries against the cited sources before relying on them. Photos are open-licence images from Wikimedia Commons; the author and licence are given with each photo.