Click on a letter above to view the list of gems.  

Hypersthene  (variety of Ferroan-Enstatite)
Current inventory:  1 gem
 

Chemistry:  (Fe,Mg)SiO₃ [Iron Magnesium Silicate]

Discovery year unkown;   IMA status: Not Valid (discredited by IMA in 1988).
The name hypersthene is from the Greek words hyper and stenos which means "over strength" or "above power" in allusion to its greater hardness than the amphibole mineral hornblende, a mineral with which it is often confused.

Classification

Mineral Classification:

Silicates

Strunz 8th Ed. ID:

8/F.02-20

Nickel-Strunz 10th Ed. ID:

9.DA.05

9 : SILICATES (Germanates)
D : Inosilicates
A : Inosilicates with 2-periodic single chains, Si₂O₆; pyroxene family

Related to:

Pyroxene Group; Orthopyroxene. Enstatite-Ferrosilite Series.

Crystal Data

Crystallography:

Orthorhombic - Dipyramidal

Crystal Habit:

Individual crystals are rare, these have a stubby prismatic habit; more typically massive or in coarse lamellar or fibrous aggregates.

Twinning:

On [100].

Physical Properties

Cleavage:

[100] Perfect, [010] Perfect

Fracture:

Uneven/Irregular

Tenacity:

Brittle

Hardness (Mohs):

5.5 - 6.0

Density:

3.2 - 3.9 (g/cm³)

Luminescence:

None

Radioactivity:

Not Radioactive

Optical Properties

Color:

Bronzy Brown, Grayish Black, Grayish White, Greenish White, Yellowish White

Transparency:

Translucent to Transparent

Luster:

Vitreous to Sub-Metallic, Pearly, Silky

Refractive Index:

1.669 - 1.773  Biaxial ( + )

Birefringence:

0.0110 - 0.0180

Dispersion:

Weak; r < v

Pleochroism:

Weak; X = pink, brownish pink, pale yellow, pale red, or colorless; Y = pinkish yellow, greenish yellow, yellow, light green, or colorless; Z = light green, bluish green, grayish green, blue, or colorless

Occurances

Geological Setting:

Dark plutonic rocks of the Adirondack Mountain region of New York, especially the North Creek garnet occurrences.

Common Associations:

Almandine Biotite, Garnet, Labradorite, Olivine, Quartz. Hypersthene is also found in iron and stony meteorites.

Common Impurities:

Ca, Na, K, Al, Co, Ni, Mn, Ti, Cr

Type Locality:

Unknown; possibly Wilson Lake, Labrador, Canada.

Year Discovered:

Unknown

View mineral photos:

Hypersthene Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Hypersthene is a member of the Pyroxene Group of minerals that includes Aegirine, Diopside, Hedenbergite, Hypersthene, Jadeite, Petedunnite and Spodumene. It is a relatively common mineral and is found in igneous and some metamorphic rocks as well as in stony and iron meteorites. It forms a solid solution series with the minerals Enstatite and Ferrosilite. A solid solution series occurs when two or more elements can substitute for each other in a crystal structure without much alteration of the structure. Enstatite is the magnesium end member of the series; Hypersthene is the intermediate member with around 50% iron; and Ferrosilite is the iron rich end member of the series.

The IMA has determined that the name Hypersthene is an unnecessary name for the intermediate member of the Enstatite-Ferrosilite series. It is regarded as a synonym of Enstatite or Ferrosilite. Most "Hypersthene" is actually Ferroan-Enstatite.

There are many localities for finding Hypersthene, but the best locations for gem quality specimens are Wilson Lake, Labrador, Canada; Bigelow Township, Labelle County, Québec, Canada; and North Creek, New York, USA.
 

  
Hypersthene gems for sale: