透輝石 · MyMineralBox

Elemental Composition (by mass)

Element	Mass %	Visual
O Oxygen	44.33%
Si Silicon	25.94%
Ca Calcium	18.51%
Mg Magnesium	11.22%

Computed from simplified end-member formula. Solid-solution series, water content, and trace substitutions cause real-world variation.

IMA Abbreviation (Whitney-Evans 2010)

→ Diopside

Ca-Mg pyroxene

Standard symbol from American Mineralogist (Whitney & Evans, 2010). Used in thin-section labeling, phase diagrams, and IMA-style species records.

Pronunciation

/daɪˈɒpsaɪd/

↔ dye-OP-side

Greek "two faces"

Diaphaneity (Transparency)

transparent-to-translucent

Chrome-diopside transparent gem.

Type Locality

Ala, Piedmont — Italy

Described 1806 by Haüy

› Browse all type localities

Specific Gravity

3.22–3.40

g/cm³

medium

Calcium-magnesium pyroxene.

For comparison: water = 1.00, glass ≈ 2.5, quartz = 2.65, corundum ≈ 4.00, galena ≈ 7.50, gold ≈ 19.3.

Pleochroism (dichroic)

Axis o

pale green

Axis e

deep green

Strength: weak

Chrome-diopside has the most visible dichroism.

Cleavage & Fracture

Cleavage:

good 2 directions ~87°/93°

Fracture:

uneven

Green pyroxene with near-90° cleavage.

Mohs 5.5–6.5

Vickers (~) 820 HV

Knoop (~) 870 HK

Geological setting

VolcanicMetamorphicSkarn

Element composition by mass

Formula: CaMgSi₂O₆ · molar mass: 216.55 g/mol

O	44.33%
Si	25.94%
Ca	18.51%
Mg	11.22%

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

GroupPyroxene Group

Related members: Augite · Jadeite · Hedenbergite · Aegirine · Enstatite · Spodumene

Mohs Hardness 5.5–6.5

1
Talc 2
Gypsum 3
Calcite 4
Fluorite 5
Apatite 6
Orthoclase 7
Quartz 8
Topaz 9
Corundum 10
Diamond

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

Colors:

Streak
White

Crystal system
Monoclinic

SilicatesSilicates (Inosilicates — Pyroxenes)

TL;DR · 1 min read

Diopside (CaMgSi₂O₆) is the calcium-magnesium end-member of the pyroxene group, one of the most abundant mineral families in Earth's crust and mantle. It forms in contact-metamorphic skarns, regional metamorphic rocks, and peridotite xenoliths brought up by volcanic eruptions.

Diopside (CaMgSi₂O₆) is the calcium-magnesium end-member of the pyroxene group, one of the most abundant mineral families in Earth’s crust and mantle. It forms in contact-metamorphic skarns, regional metamorphic rocks, and peridotite xenoliths brought up by volcanic eruptions. Crystallographic-quality Diopside specimens favor sharp prismatic crystals on white calcite-marble matrix; chrome diopside (with Cr³⁺) yields brilliant emerald-green gem material from Siberia and East Africa. China hosts notable skarn-type Diopside in Sichuan and Liaoning.

Notable Chinese Localities

Sichuan skarn deposits and Liaoning contact-metamorphic zones produce collector specimens. Outokumpu (Finland) yields chrome diopside; De Kalb (NY) supplies American material.

Cite this entry

APA

MyMineralBox Editorial Team. (2026). Diopside. My Mineral Box. Retrieved May 23, 2026, from https://mymineralbox.com/mineral-encyclopedia/minerals/diopside/

MLA

MyMineralBox Editorial Team. "Diopside." My Mineral Box, 2026, https://mymineralbox.com/mineral-encyclopedia/minerals/diopside/. Accessed May 23, 2026.

Chicago

MyMineralBox Editorial Team. "Diopside." My Mineral Box. Last modified May 5, 2026. https://mymineralbox.com/mineral-encyclopedia/minerals/diopside/.

BibTeX

@misc{mmb_diopside,
 author = {{MyMineralBox Editorial Team}},
 title = {{Diopside}},
 year = {2026},
 publisher = {My Mineral Box},
 url = {https://mymineralbox.com/mineral-encyclopedia/minerals/diopside/},
 urldate = {2026-05-23}
}