Malachite

Malachite is a green, very common secondary copper mineral with a widely variable habit. Typically, it is found as crystalline aggregates or crusts, often banded in appearance, like agates. It is also frequently found as botryoidal clusters of radiating crystals, and as mammillary aggregates as well. Single crystals and clusters of distinguishable crystals are uncommon, but when found they are typically acicular to prismatic. It is also frequently found as a pseudomorph after azurite crystals, which are generally more tabular. The Cu analogue of chukanovite. Structurally related to the Rosasite Group.

Structural context

Malachite
Crystal System monoclinicSpace Group P21/c
a9.48—9.502 (9.4947)
b11.937—11.974 (11.9617)
c3.24—3.243 (3.241)
alpha90
beta98.75—98.76 (98.7533)
gamma90
volume362.706—364.347 (363.7843)

Based on 4 measurements

Chemical context

Stoichiometric formulas

Malachite
mindat.org
  • March 13, 2023Cu2(CO3)(OH)2
IMA
  • March 13, 2023Cu2(CO3)(OH)2
mineralogy.rocks
  • Aug. 30, 2022Cu2+2CO3(OH)2

Elements recorded on EPMA

4
C
4
Cu
4
H
4
O
1
Zn

Physical properties

ColorColor entities, recognized using a custom trained NER model
  • bright green
  • yellowish green
    Color noteOriginal color note from the source
    Bright green, with crystals deeper shades of green, even very dark to nearly black; green to yellowish green in transmitted light.
    StreakStreak entities, recognized using a custom trained NER model
    • light green
    Streak noteOriginal streak note from the source
    Light green
    Lustre
    Silky
    Earthy
    Fracture
    Splintery
    Transparency
    Opaque
    Tenacity
    brittle
    Hardness
    3.5—4
    Measured density
    3.6—4.05
    Calculated density
    4