Tourmaline is famous for its wide spectrum of colors and distinct vertically striated, prism-like crystal habits. Collectors look for its unique pleochroism and its tendency to occur in bicolor or zoned patterns, often referred to as watermelon tourmaline. It is most commonly recovered from granitic pegmatites worldwide.
Is this 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 tourmaline with a known reference. 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. Tourmaline leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Tourmaline typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: black, green, pink, blue, red, yellow, colorless, multicolored.
- 5Look at form & habitCrystal system: trigonal. Typical habit: prismatic, vertically striated crystals, columnar.
Often confused with
Tourmaline vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Tourmaline is noticeably harder (Mohs 7-7.5 vs. 5-6); streak differs — Tourmaline leaves white, Hornblende leaves grayish-white.
How to tell apart: Tourmaline is noticeably harder (Mohs 7-7.5 vs. 6); streak differs — Tourmaline leaves white, Aegirine leaves yellowish-grey.
Often found alongside tourmaline
Minerals reported to co-occur with tourmaline. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na(Mg,Fe,Li,Mn,Al)₃Al₆(BO₃)₃Si₆O₁₈(OH,F)₄
- Mohs hardness
- 7-7.5
- Density
- 3.0-3.25 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Prismatic, Vertically Striated Crystals, Columnar
- Cleavage
- None
- Rarity
- Common
- Uses
- Gemstone, Collector, Industrial
- Host rock
- Granite Pegmatites, Metamorphic Schists, Hydrothermal Veins
- Typical price
- $10-100 per gram for rough, $50-5000+ for cut gemstones depending on color and clarity
Where rockhounds find tourmaline
79 mapped spotsClassic worldwide localities
- Brazil
- Madagascar
- Afghanistan
- USA
- Nigeria
- Pakistan
U.S. states with tourmaline
Each link opens a state-specific list of mapped rockhounding spots that produce tourmaline.
Field-hunting tip
Look in granite pegmatites, metamorphic schists, hydrothermal veins country — that is the host setting where tourmaline typically forms. If you start seeing quartz, feldspar, mica in float, you are in the right ground. Field specimens usually show a prismatic, vertically striated crystals, 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, Georgia, Utah — start trip planning there.
Common questions
How do you identify tourmaline?+
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Can I find tourmaline in the United States?+
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Find tourmaline on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
