530 - Chalcotrichite and Malachite

ID	530
Mineral	Chalcotrichite Malachite
Location	Sandy Flat Mine - Redbank - Northern Territory - Australia
Fluorescence	LW-UV: close SW-UV: close
Mindat.org	View Chalcotrichite information at mindat.org View Malachite information at mindat.org

ID	977
Long ID	1:1:977:9
IMA Status	0 1
Variety of	1172
Entry type	2
Description	A variety of Cuprite consisting of thin fibrous sprays or mats of hair-like crystals.
Colour	Red
Hardness (min)	3.5
Hardness (max)	4.0
Lustre	Adamantine to sub-metallic
About the name	From the Greek θρίζ "hair" and χαλκός "copper" = "hairy copper".
Crystal System	Isometric
key_elements	0

ID	2550
Long ID	1:1:2550:4
Formula	`Cu₂(CO₃)(OH)₂`
IMA Status	0 1
Other Occurrences	It is the most common secondary mineral found in the oxidized zones of copper deposits.
Industrial	A minor ore of copper when abundant enough in a copper deposit.
Discovery Year	Unno
Diapheny	Opaque
Cleavage	Perfect on {_201}, fair on {010}.
Tenacity	brittle
Colour	Bright green, with crystals deeper shades of green, even very dark to nearly black; green to yellowish green in transmitted light.
Hardness (min)	3.5
Hardness (max)	4.0
About the name	Named in antiquity (see Pliny the Elder, 79 CE) molochitus after the Greek μαλαχή, "mallows," in allusion to the green color of the leaves. Known in the new spelling, malachites, at least by 1661.
Streak	Light green
Crystal System	Monoclinic
Cleavage Type	Perfect
Fracture type	Splintery
Morphology	Crystals uncommon, usually short or long prismatic or acicular, parallel to [001]; often grouped in rosettes, sprays, or tufts. Botryoidal to mammillary aggregates of radiating fibrous crystals more common. It may also be massive, compact, and stalactitic.
Twinning	Untwinned crystals are extremely rare. Typically twinned on {100}, sometimes as penetration or polysynthetic twinning with the axis parallel to [201].
Thermal Behaviour	Loses water at about 315°, leaving tenorite.
key_elements	0
shortcode_ima	Mlc
Group	Rosasite Group

Chalcotrichite and Malachite