Brookite is a distinct titanium dioxide polymorph known for its unique orthorhombic crystal structures, often appearing as flattened, brownish-black tabular crystals. It is most prized by collectors for its occurrence in alpine-type clefts and hydrothermal settings where it forms alongside its polymorphs, rutile and anatase. Collectors should look for sharp, blade-like crystals in pockets of igneous and metamorphic rocks.
Is this brookite?
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 brookite with a known reference. Brookite sits at Mohs 5.5-6, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Brookite leaves a white to yellowish-white streak.
- 3Read the lusterHold the specimen under a strong light. Brookite typically shows a submetallic luster.
- 4Match the color rangeCompare against the expected color range: reddish-brown, brown, black, yellowish-brown.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: tabular, platy, or elongated crystals.
Often confused with
Brookite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Brookite leaves white to yellowish-white, Rutile leaves pale brown to yellow; luster reads submetallic on Brookite and metallic to adamantine on Rutile.
How to tell apart: Streak differs, so Brookite leaves white to yellowish-white, Anatase leaves white to pale yellow; luster reads submetallic on Brookite and adamantine on Anatase.
How to tell apart: Streak differs, so Brookite leaves white to yellowish-white, Manaccanite leaves black.
Often found alongside brookite
Minerals reported to co-occur with brookite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- TiO₂
- Mohs hardness
- 5.5-6
- Density
- 4.08-4.18 g/cm³
- Streak
- White to Yellowish-white
- Luster
- Submetallic
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Tabular, Platy, Or Elongated Crystals
- Cleavage
- Indistinct
- Rarity
- Uncommon
- Uses
- Collector, Scientific Study
- Host rock
- Hydrothermal Veins, Alpine-type Fissures, And Igneous Rocks
- Typical price
- $15-150 per specimen
Where rockhounds find brookite
1 mapped spotsClassic worldwide localities
- Magnet Cove, Arkansas, USA
- Alpe Devero, Italy
- Hardangervidda, Norway
- Karkonosze Mountains, Poland
Field-hunting tip
Look in hydrothermal veins, alpine-type fissures, and igneous rocks country, the host setting where brookite typically forms. If you start seeing quartz, anatase, rutile in float, you are in the right ground. Field specimens usually show a tabular, platy, or elongated crystals habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Arkansas. Start trip planning there.
Common questions
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Find brookite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
