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, so 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, 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, 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
10 mapped spotsClassic worldwide localities
- Brazil
- USA
- Namibia
- Pakistan
- Madagascar
- Germany
Field-hunting tip
Look in granite pegmatites, metamorphic schists country, 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, Texas, Arizona. 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?+
How much is black tourmaline worth?+
What rocks look like black tourmaline?+
What minerals are found with black tourmaline?+
What kind of rock does black tourmaline form in?+
What is black tourmaline used for?+
Find black tourmaline on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
