THE MINERAL HEDENBERGITE
- Chemistry: CaFeSi2 O6, Calcium Iron Silicate
- Class: Silicates
- Subclass: Inosilicates
- Group: Pyroxenes
- Uses: only as a mineral specimen.
Specimens
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
Hedenbergite although usually darker than its gemstone cousin diopside, can still be a wonderful mineral specimen. Its dark green to black color can be stricking with the bright luster that is found on some specimens. While this is not an uncommon mineral, good crystals of hedenbergite are rare and specimens that show nice crystals, good color and luster are prized.
PHYSICAL CHARACTERISTICS:
- Color is black, greenish black, dark green and dark brown.
- Luster is vitreous to dull.
- Transparency crystals are translucent to opaque.
- Crystal System is monoclinic; 2/m
- Crystal Habits include short prismatic (with a square cross section) and accicular, rarely fibrous crystals. Good crystals are rare, more commonly compact, granular, lamellar and massive.
- Cleavage is perfect in two lengthwise directions at close to right angles and a basal parting direction is sometimes seen.
- Fracture is uneven to conchoidal.
- Hardness is 5 - 6
- Specific Gravity is approximately 3.2 - 3.6 (above average)
- Streak is white to pale green.
- Associated Minerals are wollastonite, grossular, andradite, magnetite, actinolite, galena, rhodonite and calcite.
- Notable Occurrences include Fresno Co., California and Franklin New Jersey, USA; Nordmark Sweden; Broken Hill, Australia and Elba and Tuscany, Italy and Kazakhstan.
- Best Field Indicators are crystal habit, associations, color, fracture and cleavage.
 Amethyst Galleries' Mineral Gallery MINERALS |
HEDENBERGITE specimen hed-1
$ 60.00
$ 60.00
Dims: 2" x 2" x 1-1/2"
Wt: 3.9 oz
Dalnegorsk, Russia
Though the Hedenbergite in it is rather nondescript, this is still a very attractive specimen. Hedenbergite actually makes up the host rock, and takes the form of tightly compact radial clusters that splinter off into bladed prisms at their terminations. They look gray-brown and have what almost looks like a fine, grungy dust covering them. Resting amidst the terminations, however, are dozens of exceptional hexagonal bipyramids of clear beta-quartz! Really, that is the most noticeable part of the specimen, and after a while one may realize that the "host rock" is pretty special, too!
hed-1 ($ 60.00)
Dalnegorsk, Russia
HEDENBERGITE specimen hed-2
$ 30.00
$ 30.00
Dims: 2.4 x 1.7 x 1.2" (6.1 x 4.3 x 3.0 cm)
Wt: 2.84 oz. (80.6 g)
Daln'egorsk, Russia
A cluster of tabular Hedenbergite crystals makes up this specimen. They are in generally good condition- only a few are lightly damaged- and reach maximum dimensions of 0.5 x 0.5 x 0.3" (1.3 x 1.3 x 0.8 cm). All have moderately well-defined monoclinic form, but appear to be at least lightly warped due to intergrowth. They have a variable olive-green coloration, but all are covered with a thin layer of a rather soft, gray-beige material that dulls their color and gives them a greasy luster. A small amount of a pale brown, weathered host rock is attached.
hed-2 ($ 30.00)
Daln'egorsk, Russia
HEDENBERGITE specimen hed-3
$ 48.00
$ 48.00
Dims: 0.8 x 0.3 x 0.3" (2.0 x 0.8 x 0.8 cm)
Wt: 12 g w/ specimen box
South Mountain, Owyhee County, Idaho, U.S.A.
An aggregate of heavily-intergrown Hedenbergite crystals makes up this thumbnail piece. They are so intergrown that the piece is essentially a single crystal, so I will refer to it as such. It appears to have been cleaved down its length at one time, but has undergone considerable healing and is in very good condition. Its monoclinic prismatic form is excellent, and its aggregation has produced many small faces that are raised up from the main crystal faces. It has a black color with dark brown highlights and a dull, waxy luster, and it is completely opaque. There is no host rock present, and it is hot-glued inside a plastic thumbnail box.
hed-3 ($ 48.00)
South Mountain, Owyhee County, Idaho, U.S.A.
HEDENBERGITE specimen hed-4
$ 25.00
$ 25.00
Dims: 1.8 x 0.8 x 0.6" (4.6 x 2.1 x 1.5 cm)
Wt: 17 g
Turmiq, Skardu, Northern Areas, Pakistan
A single cluster of a few intersecting Hedenbergite crystals makes up this small hand specimen. The largest of these crystals dominates the cluster, measuring nearly 1.8" (4.5 cm) in length. It is in good condition, showing only minor fresh damage, but it is incomplete due to partly-healed breakage. All have reasonably good monoclinic prismatic form and a deep green color and vitreous luster. All are at least partly transparent, though most are essentially opaque due to intense including and internal fracturing. There is no host rock present.
hed-4 ($ 25.00)
Turmiq, Skardu, Northern Areas, Pakistan
HEDENBERGITE specimen hed-5
$ 40.00
$ 40.00
Dims: 2.9 x 1.9 x 1.5" (7.4 x 4.9 x 3.8 cm)
Wt: 5.8 oz. (165 g)
Keene, New York, U.S.A.
This interesting cabinet specimen consists of countless tiny, rounded Hedenbergite crystals or granules(?) that permeate a white calcite matrix. Some of these tiny pieces appear to have some discernable monoclinic form, while others are obviously amorphous. All have an olive-green coloration and a pearly luster, and appear to be translucent. There is some damage to the edges of the piece, but this can easily be "etched clean" by use of hydrochloric acid.
hed-5 ($ 40.00)
Keene, New York, U.S.A.