Black Tourmaline, also known as Schorl, is the most common variety of the tourmaline group and is easily identified by its deeply vertically striated, elongated prismatic crystals. It is a staple specimen for collectors and is frequently found embedded in quartz or granite matrices.
Is this black tourmaline?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch black tourmaline with a known reference. Black Tourmaline sits at Mohs 7-7.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Black Tourmaline leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Black Tourmaline typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: black, brownish-black.
- 5Look at form & habitCrystal system: trigonal. Typical habit: prismatic, striated, columnar.
Often confused with
Black Tourmaline vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Black Tourmaline is noticeably harder (Mohs 7-7.5 vs. 5.5-6); streak differs — Black Tourmaline leaves white, Arfvedsonite leaves grey to bluish-grey.
How to tell apart: Black Tourmaline is noticeably harder (Mohs 7-7.5 vs. 5-6); streak differs — Black Tourmaline leaves white, Hornblende leaves grayish-white.
How to tell apart: Black Tourmaline is noticeably harder (Mohs 7-7.5 vs. 5-6); streak differs — Black Tourmaline leaves white, Manaccanite leaves black; luster reads vitreous on Black Tourmaline and submetallic on Manaccanite.
Often found alongside black tourmaline
Minerals reported to co-occur with black tourmaline. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NaFe²⁺₃Al₆(Si₆O₁₈)(BO₃)₃(OH)₄
- Mohs hardness
- 7-7.5
- Density
- 2.8-3.2 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Opaque
- Crystal system
- Trigonal
- Crystal habit
- Prismatic, Striated, Columnar
- Cleavage
- Indistinct
- Rarity
- Common
- Uses
- Collector, Lapidary, Decorative
- Host rock
- Granite Pegmatites, Metamorphic Schists
- Typical price
- $5-50 thumbnail, $50-500 large cabinet
Where rockhounds find black tourmaline
7 mapped spotsClassic worldwide localities
- Brazil
- USA
- Namibia
- Pakistan
- Madagascar
- Germany
Field-hunting tip
Look in granite pegmatites, metamorphic schists country — that is the host setting where black tourmaline typically forms. If you start seeing quartz, feldspar, mica in float, you are in the right ground. Field specimens usually show a prismatic, striated, columnar habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in North Carolina, Arizona, South Carolina — start trip planning there.
Common questions
How do you identify black tourmaline?+
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Find black tourmaline on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
