RocksdayDiopside vs Hiddenite
The quickest way to tell Diopside from Hiddenite: Diopside leaves a white to greenish streak; Hiddenite leaves white.
A calcium magnesium pyroxene. Chrome diopside is a vivid green gem; black star diopside comes from India.
Photo: Didier Descouens, CC BY-SA 3.0
Green spodumene. The original North Carolina stones are colored by chromium; pale green spodumene from elsewhere is often sold under the same name.
Photo: Parent Géry, CC BY-SA 3.0
Quick tests
- Streak (rub on unglazed porcelain): Diopside leaves a white to greenish streak; Hiddenite leaves white.
Key differences
- Chrome diopside is a deeper green and a different pyroxene.
Side by side
| Property | Diopside | Hiddenite |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 5.5–6.5 | 6.5–7 |
| Luster | Vitreous | Vitreous |
| Streak | White to greenish | White |
| Colors | Green, Black, White | Green, Yellow |
| Crystal system | Monoclinic | Monoclinic |
| Specific gravity | 3.22–3.38 | 3.1–3.2 |
| Formula | CaMgSi₂O₆ | LiAlSi₂O₆ |
| Found in | Yakutia, Siberia; Pakistan | Alexander County, North Carolina; Afghanistan |
Properties that are the same for both are grayed out.
How to identify diopside
- Bright to bottle green, stubby prisms.
- Two cleavages at nearly 90°.
- Hardness about 6.
Crystal system: Monoclinic
Full Diopside guide →How to identify hiddenite
- Yellow-green to emerald-green flattened prisms.
- Two cleavages nearly at right angles.
- Hardness about 6.5–7, so a knife blade does not scratch it.
Crystal system: Monoclinic
Full Hiddenite guide →More comparisons
Frequently asked questions
What is the difference between diopside and hiddenite?
Diopside is a mineral (CaMgSi₂O₆) with a Mohs hardness of 5.5–6.5 and a vitreous luster, usually green, black or white. Hiddenite is a mineral (LiAlSi₂O₆) with a Mohs hardness of 6.5–7 and a vitreous luster, usually green or yellow.
How can you tell diopside from hiddenite?
Diopside leaves a white to greenish streak; Hiddenite leaves white. Chrome diopside is a deeper green and a different pyroxene.
Could you tell them apart from a blurry close-up?
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