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. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 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. 5-6); streak differs, so Black Tourmaline leaves white, Arfvedsonite leaves deep bluish gray, gray-green.
How to tell apart: Black Tourmaline is noticeably harder (Mohs 7-7.5 vs. 5-6); streak differs, so 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, so Black Tourmaline leaves white, Ilmenite leaves black to reddish brown; luster reads vitreous on Black Tourmaline and metallic to submetallic on Ilmenite.
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
Where rockhounds find black tourmaline
16 mapped spotsClassic worldwide localities
- Brazil
- USA
- Namibia
- Pakistan
- Madagascar
- Germany
Field-hunting tip
Where it forms: granite pegmatites, metamorphic schists. If you start seeing quartz, feldspar, mica in float, you are in the right ground. Typical habit: prismatic, striated, columnar. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in New Hampshire, North Carolina, Texas. Start trip planning there.
More black tourmaline photos
Common questions
How do you identify black tourmaline?+
Where is black tourmaline found?+
Can I find black tourmaline in the United States?+
What rocks look like 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.
