Columbite-(Mn) is a heavy, dark-colored mineral typically found in granitic pegmatites. Collectors look for its characteristic submetallic luster and sharp, tabular or prismatic crystal habits often embedded in quartz or feldspar matrices.

Hardness

Mohs

Luster

Submetallic

Streak

Reddish black

Transparency

Opaque

mineraluncommonColumbite Group family

Columbite-(Mn)

Also: Manganocolumbite

Hardness: 6
Luster: Submetallic
Streak: Reddish black
Transparency: Opaque

Is this columbite-(mn)?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch columbite-(mn) with a known reference. Columbite-(Mn) sits at Mohs 6, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: reddish black.
3
Read the luster
Hold the specimen under a strong light. Luster: submetallic.
4
Match the color range
Compare against the expected color range: black, brownish black.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: massive, prismatic, tabular.

Often confused with

Columbite-(Mn) vs. its common look-alikes, and how to tell them apart in the field.

mineral

Wolframite

Mohs 4.5

How to tell apart: Columbite-(Mn) is noticeably harder (Mohs 6 vs. 4.5).

How to tell apart: Streak differs, so Columbite-(Mn) leaves reddish black, Tantalite leaves black to reddish-brown.

Compare →

Often found alongside columbite-(mn)

Minerals reported to co-occur with columbite-(mn). Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: MnNb₂O₆
Mohs hardness: 6
Density: 5.28 g/cm³
Colors: Black Brownish black
Streak: Reddish black
Luster: Submetallic
Transparency: Opaque
Crystal system: Orthorhombic
Crystal habit: Massive, prismatic, tabular
Cleavage: Distinct on {010}; indistinct on {100}
Rarity: Uncommon
Uses: Collector, Ore of niobium, Ore of tantalum
Host rock: Constituent of granitic pegmatites

Where rockhounds find columbite-(mn)

Classic worldwide localities

Globe and Harding pegmatites, Taos County, New Mexico, USA (type locality)

Field-hunting tip

Where it forms: Constituent of granitic pegmatites. If you start seeing microcline, albite, quartz in float, you are in the right ground. Typical habit: massive, prismatic, tabular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify columbite-(mn)?+

Mohs hardness is 6. Luster: submetallic. The streak is reddish black. Common colors include black, brownish black.

Where is columbite-(mn) found?+

Notable localities include Globe and Harding pegmatites, Taos County, New Mexico, USA (type locality).

Is columbite-(mn) safe to handle?+

Contains minor amounts of radioactive elements like uranium and thorium; handle with care and wash hands after contact.

What rocks look like columbite-(mn)?+

Columbite-(Mn) is most often confused with Wolframite, Tantalite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with columbite-(mn)?+

Columbite-(Mn) commonly co-occurs with Microcline, Albite, Quartz, Beryl, Tourmaline. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does columbite-(mn) form in?+

Where it forms: Constituent of granitic pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is columbite-(mn) used for?+

Columbite-(Mn) is used in collector, ore of niobium, ore of tantalum.

Find columbite-(mn) on the map

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