Tantalite is the primary ore for tantalum, a critical metal used in high-capacity capacitors. It is identified by its heavy weight and submetallic luster, typically found as dark, tabular crystals within granitic pegmatites.
Is this tantalite?
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 tantalite with a known reference. Tantalite sits at Mohs 6, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Tantalite leaves a black to reddish-brown streak.
- 3Read the lusterHold the specimen under a strong light. Tantalite typically shows a submetallic to resinous luster.
- 4Match the color rangeCompare against the expected color range: black, brownish-black, reddish-brown.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: tabular, prismatic, or blocky crystals often with striations.
Often confused with
Tantalite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Tantalite leaves black to reddish-brown, Columbium Ore leaves dark red to black; luster reads submetallic to resinous on Tantalite and submetallic on Columbium Ore.
How to tell apart: Tantalite is noticeably harder (Mohs 6 vs. 4-4.5); streak differs, so Tantalite leaves black to reddish-brown, Wolframite leaves dark brown to black; luster reads submetallic to resinous on Tantalite and submetallic to metallic on Wolframite.
How to tell apart: Streak differs, so Tantalite leaves black to reddish-brown, Cassiterite leaves white; luster reads submetallic to resinous on Tantalite and adamantine on Cassiterite.
Often found alongside tantalite
Minerals reported to co-occur with tantalite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Fe,Mn)Ta₂O₆
- Mohs hardness
- 6
- Density
- 6.0-8.0 g/cm³
- Streak
- Black to Reddish-brown
- Luster
- Submetallic to Resinous
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Tabular, Prismatic, Or Blocky Crystals Often with Striations
- Cleavage
- Distinct in One Direction
- Rarity
- Uncommon
- Uses
- Collector, Industrial
- Host rock
- Granite Pegmatites
- Typical price
- $20-150 for thumbnail to cabinet size specimens
Where rockhounds find tantalite
1 mapped spotsClassic worldwide localities
- Brazil
- Australia
- Canada
- Democratic Republic of the Congo
- Nigeria
Field-hunting tip
Look in granite pegmatites country, the host setting where tantalite typically forms. If you start seeing microcline, albite, muscovite in float, you are in the right ground. Field specimens usually show a tabular, prismatic, or blocky crystals often with striations habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Alabama. Start trip planning there.
Common questions
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Find tantalite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
