Schorl is the most abundant species of the tourmaline group, easily recognized by its deep black color and striated, prismatic crystals. It is frequently found in granitic pegmatites and is a staple specimen for almost every mineral collection due to its durability and distinct habit.
Is this schorl?
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 schorl with a known reference. Schorl 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. Schorl leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Schorl typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: black.
- 5Look at form & habitCrystal system: trigonal. Typical habit: prismatic crystals with characteristic rounded triangular cross-sections, often vertically striated.
Often confused with
Schorl vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Schorl is noticeably harder (Mohs 7-7.5 vs. 5.5-6); streak differs, so Schorl leaves white, Arfvedsonite leaves grey to bluish-grey.
How to tell apart: Schorl is noticeably harder (Mohs 7-7.5 vs. 5-6); streak differs, so Schorl leaves white, Hornblende leaves grayish-white.
How to tell apart: Schorl is noticeably harder (Mohs 7-7.5 vs. 5.5-6); streak differs, so Schorl leaves white, Augite leaves grayish white.
Often found alongside schorl
Minerals reported to co-occur with schorl. 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)₃F
- Mohs hardness
- 7-7.5
- Density
- 3.2-3.3 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Opaque
- Crystal system
- Trigonal
- Crystal habit
- Prismatic Crystals with Characteristic Rounded Triangular Cross-sections, Often Vertically Striated
- Cleavage
- Indistinct
- Rarity
- Common
- Uses
- Collector, Lapidary, Decorative
- Host rock
- Granite Pegmatites, Hydrothermal Veins, And Metamorphic Schists
- Typical price
- $5-50 thumbnail, $20-200 cabinet specimen
Where rockhounds find schorl
11 mapped spotsClassic worldwide localities
- Erongo Mountains, Namibia
- Pederneira Mine, Brazil
- Karur, India
- Binn Valley, Switzerland
- Cornwall, England
Field-hunting tip
Look in granite pegmatites, hydrothermal veins, and metamorphic schists country, the host setting where schorl typically forms. If you start seeing quartz, microcline, albite in float, you are in the right ground. Field specimens usually show a prismatic crystals with characteristic rounded triangular cross-sections, often vertically striated habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Maine, Arizona, California. Start trip planning there.
Common questions
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Find schorl on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
