Hedenbergite

Crystal system · Monoclinic

Hedenbergite is a silicate mineral recognized among collectors for its crystal form and distribution, with known Chinese sources.

Hedenbergite specimen
Photo: Robert M. Lavinsky · CC BY-SA 3.0 via Wikimedia Commons

About Hedenbergiteextended article

Elemental Composition (by mass)
ElementMass %Visual
O Oxygen38.69%
Si Silicon22.64%
Fe Iron22.51%
Ca Calcium16.15%
Computed from simplified end-member formula. Solid-solution series, water content, and trace substitutions cause real-world variation.
IMA Abbreviation (Whitney-Evans 2010)
Hd
→ Hedenbergite
Ca-Fe pyroxene
Standard symbol from American Mineralogist (Whitney & Evans, 2010). Used in thin-section labeling, phase diagrams, and IMA-style species records.
Magnetism
Category:
weakly paramagnetic
Test result:
Strong for a non-ore silicate
Fe end-member of diopside-hedenbergite series.
Test with rare-earth magnet (N42 or N52 neodymium). Suspend specimen on thread for sensitive paramagnetic detection. Diamagnetic minerals are weakly repelled (visible only with strong magnets like bismuth).
Collector tier: Micromount / Niche
Best appreciated at thumbnail or smaller scale — often dull-colored, sub-millimeter, or radioactive. Specialist appeal.
Mohs 5.5–6.5
Vickers (~) 820 HV
Knoop (~) 870 HK
Geological setting
SkarnSedimentary
Element composition by mass

Formula: CaFeSi₂O₆ · molar mass: 248.09 g/mol

O 38.69%
Si 22.64%
Fe 22.51%
Ca 16.15%

Computed from atomic weights (IUPAC 2021). Site-occupancy groups (Fe,Mn) split equally.

GroupPyroxene Group
Related members: Augite · Diopside · Jadeite · Aegirine · Enstatite · Spodumene
Mohs Hardness 5.5–6.5

Hedenbergite sits at 5.5–6.5 on the Mohs scale — just hard enough to scratch glass.

Colors:
Streak
Gray-green
Crystal system
Monoclinic
SilicatesSilicates (Inosilicates — Pyroxenes)
TL;DR · 1 min read
Hedenbergite (CaFeSi₂O₆) is the iron-rich end-member of the diopside-hedenbergite continuous series in the calcium clinopyroxene group. It forms classic skarn assemblages at the contact between iron-rich rocks and limestone, producing dark green to black prismatic crystals on calcite or magnetite matrix.

Hedenbergite (CaFeSi₂O₆) is the iron-rich end-member of the diopside-hedenbergite continuous series in the calcium clinopyroxene group. It forms classic skarn assemblages at the contact between iron-rich rocks and limestone, producing dark green to black prismatic crystals on calcite or magnetite matrix. Famous from Nordmark (Sweden) and Sichuan/Liaoning skarn deposits.

More minerals to explore

About Hedenbergite

Hedenbergite is a silicate mineral in the pyroxene group (clinopyroxene — diopside-hedenbergite series) and has the chemical formula CaFe2+Si2O6. It crystallizes in the monoclinic system and holds a steady position among silicate species.

Identification & care

Specimens usually show prismatic, acicular needle-like crystals; radiated groups; bladed; massive. Its color range is broad, including dark green, black, brownish, and greenish black. The luster is vitreous, resinous, the streak is pale gray, and specimens range from opaque to translucent. The cleavage is good on {110} at ~87°. The fracture is uneven, which aids identification.

Collector context

Collector notes

For collectors, Hedenbergite is a benchmark crystalline species. Hedenbergite is widely represented across Chinese provinces, including Gansu, Anhui, Hebei, Guangdong.

Frequently asked questions

What is Hedenbergite?

Hedenbergite is a silicate mineral recognized among collectors for its crystal form and distribution, with known Chinese sources.

What is the chemical formula of Hedenbergite?

The chemical formula of Hedenbergite is CaFeSi2O6.

What crystal system does Hedenbergite belong to?

Hedenbergite crystallises in the Monoclinic crystal system.

Where is Hedenbergite found?

Notable localities for Hedenbergite include Huanggang Mine.

References & databases

Mindat.org is the world’s largest open mineralogy database. Our descriptions are written independently and fact-checked.