malachite cabochon from Katanga
malachite
spotted malachite from Zaire
spotted malachite from Zaire
polished malachite cabochon
malachite cabochon from Katanga
malachite
Detailed sheet
malachite
Described by Pliny in 77 AD., its name recalls and its fault, poor hardness “malakos” which means soft in Greek, as well as its green color “malake”, which means purple green in Greek.
The Egyptians, the Greeks the Romans used it since ancient times. It served as decoration, to make objects of art or of religion, and in powder, it was used as makeup or as a base for dyes.
It has a light green to dark green color, with alternating dark and light bands forming rectilinear figures or scalloped, complex, irregular. Its crystals are rare, acicular and very small, not big enough to carve translucent stones or even transparent.
It is at the Hermitage Palace in St. Petersburg that we can observe finest collections of objects made of malachite.
The Eilat stone is a mixture of malachite, chrysocolla, azurite and turquoise.
CHEMICAL CHARACTERISTICS
Cu2[CO3](OH)2
copper carbonate mineral
PHYSICAL CHARACTERISTICS
Main color
green
all shades of green in ribbons or concentric rings when it is sawed
Color of streak
green
Luster
dull, silky
Hardness
3.5 to 4.0
Density
3.20 to 4.10
Cleavage
perfect
Fracture
fibrous, uneven
OPTICAL PROPERTIES
Transparency
opaque, translucent
very small translucent crystals
Refractive index
1.655 - 1.910
Double refraction
0.254
very strong biaxial negative
visible double refraction
No
Pleochroism
very strong
Number of colors
3
colorless, green yellow, deep green
Fluorescence
none
CRYSTALS PROPERTIES
rarely crystallized, it is found in the form of aggregates of concentric layers consisting of needles. We know botryoidal nodules and stalactites.
crystals system
monoclinic
OTHER INFORMATIONS
Astrological sign
Aquarius, Aries, Capricorn, Leo
APPROACHING GEMS
Exploited
sites
This mineral is widespread and, formerly, in Russia, near Sverdloslk (Urals), same deposits have delivered blocks of over 20 tons, which, once cut, used to decorate the palaces of the tsars. We can mention Zaire, the former Katanga, which remains the world’s largest producer, but also Zambia, Australia (Queensland, New South Wales), Chile, the United States (Arizona), Namibia, Zimbabwe.
It is often associated in copper deposits with azurite, turquoise and chrysocolla.
Other
Gems
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