Provenite

About Azurite

Cu₃(CO₃)₂(OH)₂

A deep blue copper carbonate hydroxide that forms in the oxidized part of copper deposits, often together with green malachite. Crystals can reach several centimetres and are among the most sought-after blue mineral specimens; it was also the standard blue pigment before ultramarine.

Show 7 localities on the map

Photos of Azurite

Single tabular azurite crystal on matrix from the Easter pocket, Tsumeb.
Azurite · Tsumeb Mine
Single tabular azurite crystal on matrix from the Easter pocket, Tsumeb.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Azurite (chessylite) specimen from Chessy-les-Mines.
Azurite · Chessy-les-Mines
Azurite (chessylite) specimen from Chessy-les-Mines.
Photo: Didier Descouens · CC BY-SA 3.0 · Source
Azure azurite crystals on botryoidal malachite, Concepcion del Oro.
Azurite · Concepción del Oro
Azure azurite crystals on botryoidal malachite, Concepcion del Oro.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Azurite crystals lining a vug on matrix, Ting Tang Mine, Cornwall.
Azurite · Ting Tang Mine
Azurite crystals lining a vug on matrix, Ting Tang Mine, Cornwall.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Doubly terminated midnight-blue azurite crystal, Inspiration Mine, Arizona.
Azurite · Inspiration Mine
Doubly terminated midnight-blue azurite crystal, Inspiration Mine, Arizona.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Layered sky-blue scalloped azurite crust with botryoidal eyes, Cole Mine, Bisbee.
Azurite · Cole Mine (Cole shaft), Bisbee
Layered sky-blue scalloped azurite crust with botryoidal eyes, Cole Mine, Bisbee.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source

Where Azurite is found (7)

France

Mexico

Namibia

United Kingdom

United States

Azurite on the same specimen with other minerals

Same specimen Malachite with Azurite at Concepción del Oro

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

Identity

Also called
chessylite
Strunz
5 Carbonates and nitrates
IMA status
Grandfathered
Name origin
From the Persian word lazhward, a reference to the characteristic deep blue colour; the name Azurite dates from 1824.
Elements
Cu, C, O, H

Physical properties

Color
Azure-blue to Berlin blue, very dark to pale blue
Streak
Pale blue
Luster
Vitreous luster
Transparency
Variable
Mohs hardness
3.5–4
Density
3.77–3.78 g/cm³
Cleavage / fracture
Cleavage perfect but interrupted on {011}, fair on {100}, poor on {110}; fracture conchoidal; brittle

Crystallography

Crystal system
Monoclinic
Space group
P2₁/c
Structure
Monoclinic carbonate-hydroxide structure; cell a = 5.0109, b = 5.8485, c = 10.345 (angstrom), beta = 92.43 degrees, Z = 2.
Typical habit
Very varied (over 100 crystal forms recorded): tabular on {001} or prismatic crystals, rosettes, spherical or lenticular aggregates, radial stalactitic and botryoidal crusts, drusy, earthy and massive
Twinning
Rare, on {101}, {102} and {001}
Optical data
Biaxial (+); alpha = 1.730, beta = 1.754-1.758, gamma = 1.835-1.838; 2V measured about 67 degrees; strongly pleochroic in shades of blue

Formation and use

Formation
Forms in the oxidized (supergene) zone of copper deposits, especially where carbonate-rich rocks or groundwater are present. Typical associates are malachite, chrysocolla, brochantite, cuprite, cerussite, calcite and dolomite. It tends to form in drier, more acidic microenvironments than malachite.
Uses
Minor copper ore; historic blue pigment; collector specimens; azurite-malachite is cut as cabochons, inlay and carvings, faceted stones are very rare.
Stability and care
Less stable than malachite: in damp air it slowly alters to green malachite, and it can lose colour with heat, light and air exposure. Store in the dark, clean only with water, mild detergent and a soft brush, and avoid acids. Dust is toxic because of its copper content. Natural crystals are generally not treated; azurmalachite may be pore-filled or reconstituted.

Related minerals

Related minerals
Malachitechrysocollabrochantitecupritecerussite
Can be confused with
Lazuritesodalitelinariteshattuckite

Sources

  1. SRC-228 · Book
    Handbook of Mineralogy - AzuriteAnthony, J.W.; Bideaux, R.A.; Bladh, K.W.; Nichols, M.C. · 2005 · Mineralogical Society of America
  2. SRC-230 · Website
    Azurite - Open Mineral EncyclopediaMineralogical Association (Open Mineral Encyclopedia) · mineralogist.org
  3. SRC-231 · Website
    Azurite Value, Price, and Jewelry InformationInternational Gem Society · gemsociety.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.