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Mineral

Topaz

Silicate Minerals

Topaz is a silicate mineral made of aluminum and fluorine with the formula Al2SiO4(F,OH)2, a nesosilicate that crystallizes in the orthorhombic system. It is one of the hardest naturally occurring minerals and is used as a gemstone in jewelry. In its natural state it is usually colorless, often with a greyish cast, but trace impurities can make it pale blue or golden brown to yellow-orange, and heat or radiation treatment is often used to produce deep blue, reddish-orange, pale green, pink or purple stones. The pink and red varieties get their color from chromium replacing aluminium in the crystal structure. Topaz is commonly associated with silicic igneous rocks such as granite and rhyolite and crystallizes in granitic pegmatites and in gas cavities in rhyolite lava flows. Brazil and Russia are two of its most popular sources.

Facts
Formation Class
Nesosilicate, forming in granitic pegmatites, rhyolite gas cavities and high-temperature hydrothermal veins. 1
Chemical Formula
Al2SiO4(F,OH)2 1
Hardness (Mohs)
8 1
The defining mineral for 8 on the Mohs scale; its own reference article states this in the infobox rather than in prose.
Colour
Colourless or White 2
Colour
Grey or Black 2
Colour
Brown 2
Colour
Red or Pink 2
Colour
Orange or Yellow 2
Colour
Green 2
Colour
Blue or Purple 2
Lustre
Vitreous 2
Rarity
Rare 3
Classification
Strunz Class
Silicates 1
Crystal System
Orthorhombic 1
Use
Gemstone 1
Connections

Associated With

Mohs Hardness Scale, Concepts

Topaz is the defining mineral for 8 on the Mohs scale.

Source Topaz (Wikipedia)
Pegmatite, Materials

Topaz named among the characteristic minerals of complex (rare-element) pegmatites.

Source Pegmatite (Wikipedia)

Caused By

Fractional Crystallization, Processes
Source Topaz (Wikipedia)
Hydrothermal Mineral Deposition, Processes
Source EBSCO Research Starters: Hydrothermal solutions and mineralization
Volcanism, Processes
Source Topaz (Wikipedia)

Classified As

Silicate Minerals, Subcategories

Crystallizes In System

Orthorhombic Crystal System, Concepts

In Discipline

Mineralogy, Disciplines
Source Topaz (Wikipedia)
In the Other Atlases

Mineral Species Of

Yellow Topaz

Also in Divinity Atlas: of this mineral species.

Found In

Australia

Also in Geography Atlas: where this subject is found.

Source Geology.com: Topaz gemstone and mineralArticle text
Quote, Article text
Other sources of topaz include: Australia , India , Madagascar , Mexico , Myanmar , Namibia , Nigeria , Russia , and Zimbabwe
Brazil

Also in Geography Atlas: where this subject is found.

Source Geology.com: Topaz gemstone and mineralArticle text
Quote, Article text
Most of the world's imperial topaz is found in Brazil.
India

Also in Geography Atlas: where this subject is found.

Source Geology.com: Topaz gemstone and mineralArticle text
Quote, Article text
Other sources of topaz include: Australia , India , Madagascar , Mexico , Myanmar , Namibia , Nigeria , Russia , and Zimbabwe
Madagascar

Also in Geography Atlas: where this subject is found.

Source Geology.com: Topaz gemstone and mineralArticle text
Quote, Article text
Other sources of topaz include: Australia , India , Madagascar , Mexico , Myanmar , Namibia , Nigeria , Russia , and Zimbabwe
Mexico

Also in Geography Atlas: where this subject is found.

Source Geology.com: Topaz gemstone and mineralArticle text
Quote, Article text
Other sources of topaz include: Australia , India , Madagascar , Mexico , Myanmar , Namibia , Nigeria , Russia , and Zimbabwe
Myanmar

Also in Geography Atlas: where this subject is found.

Source Geology.com: Topaz gemstone and mineralArticle text
Quote, Article text
Other sources of topaz include: Australia , India , Madagascar , Mexico , Myanmar , Namibia , Nigeria , Russia , and Zimbabwe
Namibia

Also in Geography Atlas: where this subject is found.

Source Geology.com: Topaz gemstone and mineralArticle text
Quote, Article text
Other sources of topaz include: Australia , India , Madagascar , Mexico , Myanmar , Namibia , Nigeria , Russia , and Zimbabwe
Nigeria

Also in Geography Atlas: where this subject is found.

Source Geology.com: Topaz gemstone and mineralArticle text
Quote, Article text
Much topaz has been produced from placer deposits in Brazil and Nigeria
Russia

Also in Geography Atlas: where this subject is found.

Source Geology.com: Topaz gemstone and mineralArticle text
Quote, Article text
Other sources of topaz include: Australia , India , Madagascar , Mexico , Myanmar , Namibia , Nigeria , Russia , and Zimbabwe
Zimbabwe

Also in Geography Atlas: where this subject is found.

Source Geology.com: Topaz gemstone and mineralArticle text
Quote, Article text
Other sources of topaz include: Australia , India , Madagascar , Mexico , Myanmar , Namibia , Nigeria , Russia , and Zimbabwe
Sources
1. Topaz (Wikipedia)
Wikimedia Foundation
  • Lead section
    Topaz is a silicate mineral made of aluminum and fluorine with the chemical formula Al2SiO4(F, OH)2. It is used as a gemstone in jewelry and other adornments.
  • Lead section
    Topaz is a silicate mineral made of aluminum and fluorine with the chemical formula Al2SiO4(F, OH)2.
  • Lead section
    It has the orthorhombic crystal system and a dipyramidial crystal class
  • Caused By: Volcanism, Localities and occurrence
    It typically crystallizes in granitic pegmatites or in vapor cavities in rhyolite lava flows
  • Caused By: Fractional Crystallization, Localities and occurrence
    It typically crystallizes in granitic pegmatites or in vapor cavities in rhyolite lava flows
View the Source
2. minerals.net: Topaz
minerals.net
  • Color field
    Colorless, white, yellow, orange, brown, pink, light purple, gray, light blue, greenish blue, green. Occasionally multicolored.
  • Luster field
    Vitreous
View the Source
3. Geology.com: Topaz gemstone and mineral
Geology.comDescription
Quote, Description
Topaz is a rare silicate mineral
View the Source
Wikidata: Topaz
Wikidata Q134985
Pegmatite (Wikipedia)
Wikimedia FoundationAssociated With: Pegmatite, Complex pegmatite mineralogy section
Quote, Associated With: Pegmatite, Complex pegmatite mineralogy section
These complex pegmatites contain unusual minerals of these elements, such as beryl, spodumene, lepidolite, amblygonite, topaz, apatite, fluorite, tourmaline.
View the Source
EBSCO Research Starters: Hydrothermal solutions and mineralization
EBSCO Research StartersCaused By: Hydrothermal Mineral Deposition, Hydrothermal deposit types and gangue minerals
Quote, Caused By: Hydrothermal Mineral Deposition, Hydrothermal deposit types and gangue minerals
Hypothermal or high-temperature and high-pressure mineral assemblages include the minerals cassiterite (tin), scheelite and wolframite (tungsten), millerite (nickel), and molybdenite (molybdenum), associated with gangue minerals quartz, tourmaline, topaz, and other silicates.
View the Source
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