Tantalite-(Mn) is a heavy, dark-colored mineral typically found as well-formed prismatic crystals in complex granite pegmatites. It is the primary ore for tantalum and is highly valued by collectors for its sharp, geometric crystal shapes and high density.
Is this tantalite-(mn)?
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-(mn) with a known reference. Tantalite-(Mn) 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-(Mn) leaves a reddish-brown to black streak.
- 3Read the lusterHold the specimen under a strong light. Tantalite-(Mn) typically shows a submetallic to resinous luster.
- 4Match the color rangeCompare against the expected color range: black, brown, reddish-brown.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: tabular to prismatic crystals, often with complex faces.
Often confused with
Tantalite-(Mn) vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Tantalite-(Mn) leaves reddish-brown to black, Columbite-(Fe) leaves dark red to black; luster reads submetallic to resinous on Tantalite-(Mn) and submetallic to metallic on Columbite-(Fe).
How to tell apart: Tantalite-(Mn) is noticeably harder (Mohs 6 vs. 4-4.5); streak differs — Tantalite-(Mn) leaves reddish-brown to black, Wolframite leaves dark brown to black; luster reads submetallic to resinous on Tantalite-(Mn) and submetallic to metallic on Wolframite.
Often found alongside tantalite-(mn)
Minerals reported to co-occur with tantalite-(mn). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- MnTa₂O₆
- Mohs hardness
- 6
- Density
- 7.3-8.0 g/cm³
- Colors
- Streak
- Reddish-brown to Black
- Luster
- Submetallic to Resinous
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Tabular to Prismatic Crystals, Often with Complex Faces
- Cleavage
- Distinct in One Direction
- Rarity
- Uncommon
- Uses
- Ore of Tantalum, Collector Specimen
- Host rock
- Granite Pegmatites
- Typical price
- $20-150 for thumbnail to cabinet specimens
Where rockhounds find tantalite-(mn)
Classic worldwide localities
- Brazil
- Nigeria
- Australia
- Democratic Republic of the Congo
- USA
Field-hunting tip
Look in granite pegmatites country — that is the host setting where tantalite-(mn) typically forms. If you start seeing albite, microcline, muscovite in float, you are in the right ground. Field specimens usually show a tabular to prismatic crystals, often with complex faces habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify tantalite-(mn)?+
Where is tantalite-(mn) found?+
How much is tantalite-(mn) worth?+
Is tantalite-(mn) safe to handle?+
What rocks look like tantalite-(mn)?+
What minerals are found with tantalite-(mn)?+
What kind of rock does tantalite-(mn) form in?+
What is tantalite-(mn) used for?+
Find tantalite-(mn) on the map
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