Name/Title
Azurite with MalachiteEntry/Object ID
2009.62.225Description
Chemical Composition: Cu3(CO3)2()H2
Crystal System: Monoclinic System
Description: Common Name: Azurite / Malachite
Chemistry: Cu3(CO3)2(OH)2, / Cu2(CO3)(OH)2 , Copper Carbonate Hydroxide (both)
Group: Carbonates
Location: Arizona
Description: Dark blue base color (azurite) with some turquoise spots (malachite).
PHYSICAL CHARACTERISTICS OF AZURITE:
Color is azure, deep blue or pale blue if found in small crystals or crusts.
Luster is vitreous to dull depending on habit.
Transparency: Transparent if in thin crystals, otherwise translucent to opaque.
Crystal System is monoclinic; 2/m.
Crystal Habits crystals are irregular blades with wedge shaped terminations. Also, aggregate crusts and radiating, botryoidal, nodular and earthy masses.
Cleavage is good in one direction and fair in another.
Fracture is conchoidal and brittle.
Hardness is 3.5-4.
Specific Gravity is 3.7+ (heavier than average).
Streak is blue.
Associated Minerals are numerous and include malachite limonite, calcite, cerussite, quartz, chalcopyrite, native copper, cuprite, chrysocolla, aurichalcite, shattuckite, liroconite, connellite and other oxidized copper minerals.
Best Field Indicators are color, softness, crystal habits and associations.
THE PHYSICAL CHARACTERISTICS OF MALACHITE:
Color is banded light and dark green or (if crystalline), just dark green.
Luster is dull in massive forms and silky as crystals.
Transparency is opaque in massive form and translucent in crystalline forms.
Crystal System is monoclinic; 2/m.
Crystal Habitsin its massive forms are botryoidal, stalactitic or globular. Crystals are acicular or fibrous and form in tufts and encrustations. Frequently found as pseudomorphs of azurite.
Cleavage is good in one direction but rarely seen.
Fracture is conchoidal to splintery.
Hardness is 3.5-4.
Specific Gravity is 3.9+ (slightly heavy).
Streak is green.
Other Characteristics: Weakly effervesces in acid.
Associated Minerals include limonite, chalcopyrite, bornite, native copper, calcite, cuprite, azurite, chrysocolla and many rare copper minerals such as kolwezite, shattuckite, antlerite, brochantite, graemite, aurichalcite, sphaerocobaltite, atacamite, chalcophyllite, conichalcite, rosasite, chalcosiderite, clinoclase, cornetite, duftite, libethenite, liroconite, mixite and mottramite among others.
Best Field Indicators are color banding, softness, associations and reaction to acid.
Fracture: Conchoidal
Hardness: 4 Fluorite
Luster: Vitreous
Occurrence: Azurite is a very popular mineral because of its unparalleled color, a deep blue called "azure", hence its name. Azure is derived from the Arabic word for blue. The color is due to the presence of copper (a strong coloring agent), and the way the copper chemically combines with the carbonate groups (CO3) and hydroxyls (OH). Azurite has been used as a dye for paints and fabrics for eons. Unfortunately, at times its color is too deep and larger crystals can appear black. Small crystals and crusts show the lighter azure color well. Azurite is often associated with its colorful close cousin, malachite.
Green malachite is closely associated with azurite in many ways. Not only do they frequently occur together (pictured above), they also have very similar formulae. Malachite can also replace azurite, making a pseudomorph, or an exact copy of an azurite crystal (only now instead of being blue, it would be green). Compare their formulas:
Azurite's formula: Cu3(CO3)2(OH)2
Malachite's formula: Cu2(CO3)(OH)2
Specific Gravity: 3.7
Streak: WhiteCollection
RAGM Mineral CollectionAcquisition
Accession
2009.62Source or Donor
Museum Collection of MineralsAcquisition Method
DonationDimensions
Width
9 inDepth
2 inLength
9-1/4 inLocation
Location
Wall
NorthBuilding
Storage (old gift shop upstairs)Category
PermanentMoved By
Rawley WyattDate
May 21, 2014Location
Container
rightDrawer
bottom tierShelf
east side, east sideWall
centerRoom
Delmar Smith HallBuilding
Crater Rock MuseumCategory
PermanentMoved By
Wendy MondryDate
January 6, 2010Location
Cabinet
H-6 rearWall
NorthBuilding
HStorage (old gift shop upstairs)Category
Permanent
