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Quartz Family
Current inventory:  0 gems
 

Quartz Family

  
Quartz is named from the German word quarz (of uncertain origin). The word crystal was originally used only for Quartz and is from the Greek word krystallos, meaning ice, because the Greeks thought the gods had created an unnatural frost that froze ice hard forever.

Prehistoric Discovery; IMA status: Valid (pre-IMA; Grandfathered)

 

Chemistry

 

 

Chemical Formula:

SiO2

 

Silicon Dioxide

Molecular Weight:

60.08 gm

Composition:

Silicon

46.74 %

Be

100.00 %

SiO2

 

Oxygen

53.26 %

O

 

 

 

 

100.00 %

 

100.00 %

= TOTAL OXIDE

 

 

Classification

   

   

Mineral Classification:

Oxides

Strunz 8th Ed. ID:

4/D.01-10

Nickel-Strunz 10th Ed. ID:

4.DA.05

 

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
A : With small cations: Silica family
 

Related to:

Polymorph of Coesite, Cristobalite, Mogánite, Seifertite, Stishovite, Tridymite. Isostructural with Berlinite.
 

Varieties: 

Abakusz-kö, Agate, Agate-Jasper, Agatized coral, Amarillo Stone, Amberine, Amethyst, Ametrine, Apricotine, Arkansas Candle, Aventurine, Azurchalcedony, Babel-Quartz, Ball Jasper, Basanite, Bayate, Beekite, Binghamite, Bloodstone, Blue Chalcedony, Blue Lace Agate, Blue Quartz, Botswana Agate, Brazilian Pebble, Brecciated Agate, Bristol Diamonds, Buhrstone, Bull Quartz, Burnt Amethyst, Cactus Quartz, Cape May Diamonds, Capped Quartz, Carnelian, Chalcedony, Chrome-Chalcedony, Chrysojasper, Citrine, Clear Lake Diamonds, Cloud Agate, Cotterite, Crazy Lace Agate, Creolite, Cubosilicite, Dallasite, Damsonite, Darlingite, Dendritic Agate, Diackethyst, Dragonite, Egyptian Jasper, Eisenkiesel, El Doradoite, Enhydro Agate, Eye Agate, Fairburn Agate, Fensterquarz, Ferruginous Quartz, Fire Agate, Fortification Agate, Fossil Agate, Gwindel, Haema-ovoid-agates, Hair Amethyst, Haytorite, Hedgehog Stone, Herbeckite, Herkimer Diamond, Herradura Diamonds, Iris Agate, Iris Quartz, Irnimite, Jacinto de Compostela Quartz, Jasper, Keystonite Chalcedony, Kinradite, Laguna Agate, Lake County Diamonds, Lake Superior Agate, Landscape Agate, Lithium Quartz, Marmaroscher Diamanten, Mexican Lace Agate, Milky Quartz, Mocha Stone, Moss Agate, Mutzschen Diamonds, Myrickite, Nipomo Agate, Oil Quartz, Onyx, Owyhee Jasper, Pastelite, Pietersite, Pigeon Blood Agate, Plasma, Plume Agate, Prase, Prase-malachite, Prasiolite, Pseudocubic Quartz, Quartzine, Quetzalitztli, Riband Agate
 

Synonyms:

α-Quartz, Alpha-Quartz, Azetulite, Azeztulite, β-Quartz (of Geophys. Lab), Brazillian Pebble, Conite (of Macculloch), Cornish Diamond, Konilite, Lemurian Seed Crystal, Lodolite, Low Quartz, Mexican Diamond, Quartz-alpha, Quartz-α, Quertz

 

 

Crystal Data

   

   

Crystallography:

Trigonal - Trapezohedal

Crystal Habit:

Widely variable; but typically long prismatic with steep pyramidal terminations, but may be short prismatic to nearly bipyramidal; fibrous (Agate & Chalcedony)

Twinning:

Very common, penetration twins on the Dauphiné law, about [0001], and the Brazil law, with [1120] as contact plane; contact twins on the Japan law, with [1122] as contact plane, may be repeated; and several other laws.

 

 

Physical Properties

   

 

Cleavage:

[0110] Indistinct

Fracture:

Conchoidal

Tenacity:

Brittle, tough when massive

Moh's Hardness:

7.0

Density:

2.60 - 2.65 (g/cm3)

Luminescence:

Fluorescent; Shortwave UV = yellow-orange, Longwave UV = yellow-orange.
May be Triboluminescent

Radioactivity:

Not Radioactive

Other:

Piezoelectric and Pyroelectric and may be Triboluminescent

 

 

Optical Properties

   

   

Color:

Colorless, white, gray, and many shades of violet, purple, yellow, orange, red, brown, pink, green, blue and black

Transparency:

Transparent to nearly Opaque

Luster:

Vitreous, waxy to dull when massive

Refractive Index:

1.543 - 1.554  Uniaxial ( + )

Birefringence:

0.0090

Dispersion:

0.013 (low)

Pleochroism:

Quartz: none; Amethyst: weak; Citrine: weak; Rose Quartz: strong

 

 

Occurances

   

   

Geological Setting:

In hydrothermal veins, epithermal to alpine; characteristic of granites and granite pegmatites; in sandstones and quartzites, less abundant in other rock types; in hydrothermal metal deposits. Common in carbonate rocks; a residual mineral in soils and sediments.

Common Associations:

Calcite, Chlorite, Epidote, Feldspars, Fluorite, Micas, Zeolites, many other species.

Type Locality:

n/a

Year Discovered:

Prehistoric

View mineral photos:

Quartz Mineral Photos and Locations

 

 

More Information

   

   

 

Mindat.org
Webmineral.com

 

 


Quartz is one of the most common minerals on Earth. It is composed of silicon and oxygen, the two most abundant elements in the crust of the Earth. Quartz comes in many colors including purple/violet (Amethyst); yellow and purple (Ametrine); yellow/orange (Citrine); pink (Rose Quartz); brown (Smoky Quartz); green (
Prasiolite) and colorless (Rock Crystal). The various colors are due to trace elements added to the basic Silicon Dioxide formula. Quartz also has many attractive and collectable inclusions (see below) created by the addition of other minerals such as Actinolite,  Gilalite, Lepidocrocite, Pyrite, Rutile, Tourmaline and many others. Quartz catseyes and stars are also available and are created by the presence of fine asbestos or rutile fibers. Quartz gems have been faceted in enormous sizes. The Smithsonian Institute (SI) has a perfect sphere of flawless Burmese Rock Crystal that is 12.75 inch in diameter and weighs 107 pounds. SI also has a 7000 carat faceted Quartz, a 2258 carat Brazilian Citrine, a 4500 carat Smoky Quartz and a 1362 carat Brazilian Amethyst!
 

 


Quartz varieties

 

 

 

 

 

 

 

 

 

Adventurine

 

Agate

 

Amethyst

 

Ametrine
Adventurine

 

Agate

 

Amethyst

 

Ametrine

 

 

 

 

 

 

 

Bloodstone

 

Carnelian

 

Chalcedony

 

Chert
Bloodstone

 

Carnelian

 

Chalcedony

 

Chert

 

 

 

 

 

 

 

Chrysoprase

 

Citrine

 

Flint

 

Poppy Jasper
Crysoprase

 

Citrine

 

Flint

 

Jasper

 

 

 

 

 

 

 

Moss Agate

 

Onyx

 

Prase

 

Quartz
Moss Agate

 

Onyx

 

Prase

 

Quartz

 

 

 

 

 

 

 

Rose Quartz

 

Sardonyx

 

Smoky Quartz

 

Tiger eye
Rose Quartz

 

Sardonyx

 

Smoky Quartz

 

Tiger Eye

 

 

 

 

 

 

 

 


Inclusions in Quartz

 

 

 

  
Quartz crystals grow in many different environments along with many different minerals. These minerals, as well as gas bubbles, water and petroleum solutions, can become enclosed or trapped within the growing Quartz crystals. These "inclusions" have become a very popular gem collecting category with incredible beauty and variety. Below are some of the many types of inclusions found in Quartz gems.

 

 

 

 

 

 

 

Actinolite in Quartz

 

Ajoite in Quartz

 

Anatase in Quartz

 

Ankangite in Quartz
Actinolite (incl.)

 

Ajoite (incl.)

 

Anatase (incl.)

 

Ankangite (incl.)

 

 

 

 

 

 

 

Bismuthinite in Quartz

 

Brookite in Quartz

 

Cacoxenite in Quartz

 

Calcite in Quartz
Bismuthinite (incl.)

 

Brookite (incl.)

 

Cacoxenite (incl.)

 

Calcite (incl.)

 

 

 

 

 

 

 

Celadonite in Quartz

 

Cervantite in Quartz

 

Chlorite in Quartz

 

Chrysocolla in Quartz (Gem Silica)
Celadonite (incl.)

 

Cervantite (incl.)

 

Chlorite (incl.)

 

Chrysocolla (incl.)

 

 

 

 

 

 

 

Cleavelandite in Quartz

 

Connellite in Quartz

 

Cookeite in Quartz

 

Dendrites in Quartz
Cleavelandite (incl.)

 

Connellite (incl.)

 

Cookeite (incl.)

 

Dendrites (incl.)

 

 

 

 

 

 

 

Dumortierite

 

Epidote in Quartz

 

Fluorite in Quartz

 

Gilalite in Quartz
Dumortierite (incl.)

 

Epidote (incl.)

 

Fluorite (incl.)

 

Gilalite (incl.)

 

 

 

 

 

 

 

Goethite in Quartz

 

Hedenbergite in Quartz

 

Helvine in Quartz

 

Hematite in Quartz
Goethite (incl.)

 

Hedenbergite (incl.)

 

Helvine (incl.)

 

Hematite (incl.)

 

 

 

 

 

 

 

Hollandite in Quartz

 

Indicolite in Quartz

 

Jamesonite in Quartz

 

Lazulite in Quartz
Hollandite (incl.)

 

Indicolite (incl.)

 

Jamesonite (incl.)

 

Lazulite (incl.)

 

 

 

 

 

 

 

Lepidicrocite in Quartz

 

Lithiophilite in Quartz

 

Lodolite Quartz

 

Macfallite in Quartz
Lepidocrocite (incl.)

 

Lithiophilite (incl.)

 

Lodolite (incl.)

 

Macfallite (incl.)

 

 

 

 

 

 

 

Marcasite in Quartz

 

Molybdenite in Quartz

 

Montmorillonite in Quartz

 

Petroleum in Quartz
Marcasite (incl.)

 

Molybdenite (incl.)

 

Montmorillonite (incl.)

 

Petroleum (incl.)

 

 

 

 

 

 

 

Prase

 

Pyrite in Quartz

 

Pyrophyllite in Quartz

 

Quartz in Quartz
Prase (incl.)

 

Pyrite (incl.)

 

Pyrophyllite (incl.)

 

Quartz in Quartz (incl.)

 

 

 

 

 

 

 

Rutile in Quartz

 

Tourmaline in Quartz

 

Trolleite in Quartz

 

 

Rutile (incl.)

 

Tourmaline (incl.)

 

Trolleite (incl.)

 

 

 

 

 

 

 

 

 

 

  
Quartz Family varieties

Adventurine

colorful, but barely translucent, type of Chalcedony 
 

Agate

banded or patterned variety of Chalcedony; there are many names given to the various patterns of Agate: Dendritic, Fire, Lace, Moss, Scenic, Shell, Turritella (fossil or silicified shells), etc. Other names are due to the location of origin.
 

Amethyst

colored Quartz; pale lilac (Rose of France), violet, purple, deep purple with red flashes (Siberian)
 

Ametrine

colored Quartz; both yellow and purple colors in zonal patterns
 

Bloodstone

also known as Heliotrope; dark green Plasma with blood-red and orange spots of iron oxides
 

Carnelian

translucent to semiopaque red, orange or brownish type of Chalcedony colored by the presence of iron oxide
 

Cat's Eye

chatoyant due to asbestos or rutile fibers
 

Chalcedony

microcrystalline Quartz; grayish blue, blue, purplish blue
 

Chert

cryptocrystalline Quartz; opaque, dull gray or whitish Chalcedony; very hard
 

Chrysoprase

apple green type of Chalcedonly; colored by presence of nickel
 

Citrine

colored Quartz; pale yellow, yellow, golden yellow, yellow-orange
 

Dinosaur Bone

silicified dinosaur bone; brownish, red, pink, blue, purple, green, orange, etc.
 

Flint

cryptocrystalline Quartz; opaque, dull gray or whitish Chalcedony; very hard
 

Hornstone

flint
 

Jasper

patterned variety of Chalcedony; shades of red, brown, yellow and green; there are many names given to the various patterns of Jasper: Orbicular, Picture, Scenic, etc. Other names are due to the location of origin.
 

Milky Quartz

milky due to many tiny cavities and bubbles filled with CO2 or water; may also contain Gold
 

Moss Agate

a variety of Agate with "mossy" inclusions
 

Onyx

opaque black and white banded type of Chalcedony
 

Plasma

deep green Chalcedony (opaque due to densely packed actinolite crystals)
 

Petrified Wood

colorful Agate that has replaced tree trunks and limbs
 

Prase

green or yellowish green type of Chalcedony
 

Rock Crystal

colorless, white
 

Rose Quartz

pale to deep pink (due to titanium)
 

Sapphire Quartz

blue Quartz
 

Sard

similar to Carnelian but more brownish and more opaque
 

Sardonyx

banded Onyx with red and white layers
 

Smokey Quartz

pale beige, tan, brown, deep brown (Cairngorm), black
 

Tiger Eye

pseudomorph of asbestos
 


 

 


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