Comparison · Minerals vs Silicate Minerals
Diopside vs Spodumene
Diopside and Spodumene are easy to confuse. Both sit near Mohs 5.5–6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Diopside and Spodumene
- Both sit near Mohs 5.5–6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Hold a thin edge to the light: Diopside is Transparent to translucent, Spodumene is transparent.
- They overlap in green and purple, but Diopside also comes in white, gray, blue, black, and multicolored and Spodumene also comes in pink, yellow, and clear.
- Well-formed crystals give it away: Diopside is Monoclinic, Spodumene is monoclinic.
Diopside vs Spodumene properties
| Property | Diopside | Spodumene |
|---|---|---|
| Type | Minerals | Silicate Minerals |
| Mohs hardness | 5.5–6.5 | 6.75 |
| Luster | Vitreous | vitreous |
| Streak | White | White |
| Transparency | Transparent to translucent | transparent |
| Specific gravity | 3.2–3.3 | 3.15 |
| Crystal system | Monoclinic | monoclinic |
| Common colors | Light to dark green, White, Gray, Blue-violet (violane), Black (chromian varieties) | Pink, Lilac, Green, Yellow, Colorless |
| Rarity | common | uncommon |
| Typical specimen value | $2–$150+ | $10–$800+ |
Which is more valuable?
Spodumene is usually the more valuable of the two: a typical collector specimen runs about $110 against $20 for Diopside, and premium Spodumene can reach $800 or more.
About Diopside
Diopside is a calcium magnesium silicate pyroxene mineral, CaMgSi2O6, common in metamorphosed limestones and mafic to ultramafic igneous rocks. It typically forms stubby prismatic crystals with a nearly square cross-section, a hallmark of the pyroxene group's characteristic cleavage angles. Diopside's color ranges from colorless to deep green depending on iron and chromium content, and chromium-rich varieties are prized as gem material.
About Spodumene
Spodumene is a lithium aluminum pyroxene found in granite pegmatites. It forms flattened prismatic crystals with perfect prismatic cleavage, and its transparent gem varieties include pink-lilac kunzite and green hiddenite.
Diopside vs Spodumene FAQ
Is Diopside the same as Spodumene?
No. Diopside is a mineral while Spodumene is a silicate mineral. Both sit near Mohs 5.5–6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Diopside from Spodumene?
Both sit near Mohs 5.5–6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Hold a thin edge to the light: Diopside is Transparent to translucent, Spodumene is transparent. They overlap in green and purple, but Diopside also comes in white, gray, blue, black, and multicolored and Spodumene also comes in pink, yellow, and clear.
Which is harder, Diopside or Spodumene?
Spodumene is harder: Mohs 6.75 against Mohs 5.5–6.5 for Diopside.
Which is more valuable, Diopside or Spodumene?
Spodumene is usually the more valuable of the two: a typical collector specimen runs about $110 against $20 for Diopside, and premium Spodumene can reach $800 or more.
