PHYSICAL PROPERTIES:
Chemistry: CaFeSi2
O6
Composition: Calcium Iron Silicate
Class: Silicates
Subclass: Inosilicates
Group: Pyroxenes
Crystal system: monoclinic
Fracture: uneven to conchoidal
Hardness: 5 - 6
Specific gravity:3.2 - 3.6
Refractive Index:
Pleochroism:
Luster: Luster is vitreous to dull
Streak: white to pale green
Cleavage: perfect in two lengthwise directions
Color: black, greenish black, dark green
and dark brown
Transparency: translucent to opaque
Associated Minerals: actinolite,
andradite, calcite, galena, grossular garnet, magnetite, rhodonite and
wollastonite
COMPOSITION:
DIOPSIDE:Calcium magnesium silicate (25.9% CaO, 18.5% MgO, 55.6%
Si02). Iron may replace some or all of the magnesium,
darkening the crystal and forming the variety Hedenbergite.
DISTINGUISHING CHARACTERISTICS:
Hedenbergite is a part of an important solid solution series
of the pyroxene group. The series includes the minerals diopside, CaMgSi2
O6, and augite, (Ca, Na)(Fe, Mg, Al)(Al, Si)2
O6. Hedenbergite is the iron rich end member
of the series. The diopside-hedenbergite series is analogous to the
amphiobole, tremolite- actinolite series. Hedenbergite is usually darker
than its gemstone cousin diopside. Good crystals of hedenbergite are
rare and specimens that show nice crystals, good color and luster are
prized.
ENVIRONMENT:
Hedenbergite occurs in contact metamorphic rocks bearing iron minerals.
It is associated
with ilvaite, garnets, sulfides, epidote and calcite. Hedenbergite is
a member of the pyroxene group, which is an important and widely distributed
group of rock-forming silicates. found in several metamorphic rocks,
especially contact metamorphic rocks and skarns. It is also found in
some igneous rocks and ore bodies.
CRYSTAL DESCRIPTION:
Hedenbergite crystals commonly occur as radiating fibrous aggregates,
with stubby, prismatic crystals of nearly square cross section being
rarer. They are almost opaque except when slivers viewed on the edge.
Fibrous forms are often greenish-brown in color
TESTS:
LOCALITIES:
The specimens we curently have for sale are from
South Mountain, Owyhee Co., Idaho.
Other well known localities include, fine crystals from the Laxey
mine Iron Hill, Gunnison Co., Colorado.The Westinghouse mine, Santa
Cruz Co., Arizona, Grant Co., New Mexico, Fresno Co., California and
Franklin New Jersey. Nordmark Sweden; Broken Hill, Australia
and Elba and Tuscany, Italy and Kazakhstan.
USES:
As a mineral specimen.
FACTS & HISTORY:
Named after the Swedish chemist, M.A. Ludwig Hedenberg, who first
described the species.
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