RocksdayBlack Tourmaline vs Dravite
To tell Black Tourmaline from Dravite: Schorl is blacker and is the iron species, typical of granites.
Schorl, the iron tourmaline and the most common species of the group. Opaque black prisms with a triangular cross-section.
Photo: Parent Géry, CC BY-SA 3.0
Magnesium tourmaline, usually brown. It often grows in marble rather than in granite pegmatites.
Photo: Robert M. Lavinsky, CC BY-SA 3.0
Key differences
- Schorl is blacker and is the iron species, typical of granites.
Side by side
| Property | Black Tourmaline | Dravite |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 7–7.5 | 7–7.5 |
| Luster | Vitreous | Vitreous |
| Streak | White | White |
| Colors | Black | Brown, Black, Yellow, Green |
| Crystal system | Trigonal | Trigonal |
| Specific gravity | 3.1–3.25 | 3–3.2 |
| Formula | NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄ | NaMg₃Al₆(BO₃)₃Si₆O₁₈(OH)₄ |
| Found in | Erongo, Namibia; Minas Gerais, Brazil | Drava region, Slovenia; Yinnietharra, Western Australia |
Properties that are the same for both are grayed out.
How to identify black tourmaline
- Black prisms with lengthwise grooves.
- A broken end is a rounded triangle, not a circle.
- Hard — scratches glass. White streak, not black.
- No cleavage. A magnet does not stick.
Crystal system: Trigonal
Full Black Tourmaline guide →How to identify dravite
- Brown prisms with a triangular cross-section and lengthwise grooves.
- Hardness 7–7.5.
- Commonly in pale metamorphic rocks.
Crystal system: Trigonal
Full Dravite guide →More comparisons
Frequently asked questions
What is the difference between black tourmaline and dravite?
Black Tourmaline is a mineral with a Mohs hardness of 7–7.5 and a vitreous luster, usually black. Dravite is a mineral with a Mohs hardness of 7–7.5 and a vitreous luster, usually brown, black, yellow or green.
How can you tell black tourmaline from dravite?
Schorl is blacker and is the iron species, typical of granites.
Could you tell them apart from a blurry close-up?
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