RocksdayBlack Tourmaline vs Tourmaline
To tell Black Tourmaline from Tourmaline: Gem tourmaline is the same group in green, pink or other colors; schorl is the black species.
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
A boron-bearing silicate found in more colors than almost any other gem. Black schorl is the most common form.
Photo: Robert M. Lavinsky, CC BY-SA 3.0
Key differences
- Gem tourmaline is the same group in green, pink or other colors; schorl is the black species.
- Schorl is the black iron species. Gem colors are usually elbaite.
Side by side
| Property | Black Tourmaline | Tourmaline |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 7–7.5 | 7–7.5 |
| Luster | Vitreous | Vitreous |
| Streak | White | White |
| Colors | Black | Black, Green, Pink |
| Crystal system | Trigonal | Trigonal |
| Specific gravity | 3.1–3.25 | 3–3.3 |
| Formula | NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄ | Complex borosilicate |
| Found in | Erongo, Namibia; Minas Gerais, Brazil | Mount Mica, Maine; San Diego County, California |
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 tourmaline
- Long prisms with lengthwise grooves (striations).
- Rounded-triangle cross-section when broken across.
- Hard — scratches glass.
- Gem crystals can change color from end to end ('watermelon').
Crystal system: Trigonal
Full Tourmaline guide →More comparisons
Frequently asked questions
What is the difference between black tourmaline and tourmaline?
Black Tourmaline is a mineral with a Mohs hardness of 7–7.5 and a vitreous luster, usually black. Tourmaline is a mineral (Complex borosilicate) with a Mohs hardness of 7–7.5 and a vitreous luster, usually black, green or pink.
How can you tell black tourmaline from tourmaline?
Gem tourmaline is the same group in green, pink or other colors; schorl is the black species. Schorl is the black iron species. Gem colors are usually elbaite.
Could you tell them apart from a blurry close-up?
Play today's Rocksday