RocksdayBabingtonite vs Black Tourmaline
The quickest way to tell Babingtonite from Black Tourmaline: Black Tourmaline is clearly harder: Mohs 7–7.5 versus 5.5–6.
A black calcium-iron silicate of short, shiny prisms. It is the official mineral of Massachusetts.
Photo: Didier Descouens, CC BY-SA 3.0
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
Quick tests
- Hardness: Black Tourmaline is clearly harder: Mohs 7–7.5 versus 5.5–6.
- Streak (rub on unglazed porcelain): Babingtonite leaves a brown streak; Black Tourmaline leaves white.
Key differences
- Schorl is harder, has a white streak and does not grow in basalt cavities this way.
Side by side
| Property | Babingtonite | Black Tourmaline |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 5.5–6 | 7–7.5 |
| Luster | Vitreous | Vitreous |
| Streak | Brown | White |
| Colors | Black, Green | Black |
| Crystal system | Triclinic | Trigonal |
| Specific gravity | 3.3–3.4 | 3.1–3.25 |
| Formula | Ca₂(Fe,Mn)FeSi₅O₁₄(OH) | NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄ |
| Found in | Arendal, Norway; Somerville, Massachusetts | Erongo, Namibia; Minas Gerais, Brazil |
Properties that are the same for both are grayed out.
How to identify babingtonite
- Small black or very dark green prisms, often on prehnite or zeolites.
- Brown streak.
- Hardness 5.5–6. A strong magnet may tug weakly.
Crystal system: Triclinic
Full Babingtonite guide →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 →More comparisons
Frequently asked questions
What is the difference between babingtonite and black tourmaline?
Babingtonite is a mineral with a Mohs hardness of 5.5–6 and a vitreous luster, usually black or green. Black Tourmaline is a mineral with a Mohs hardness of 7–7.5 and a vitreous luster, usually black.
How can you tell babingtonite from black tourmaline?
Black Tourmaline is clearly harder: Mohs 7–7.5 versus 5.5–6. Babingtonite leaves a brown streak; Black Tourmaline leaves white. Schorl is harder, has a white streak and does not grow in basalt cavities this way.
Could you tell them apart from a blurry close-up?
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