Niobocarbide is an extremely rare transition metal carbide found primarily as microscopic grains within kimberlite pipes. Due to its extreme hardness and high density, it is typically identified via electron microprobe analysis rather than visual inspection. It occurs naturally in mantle-derived rocks and is highly valued for its geochemical significance.

Hardness

8-9

Mohs

Luster

Metallic

Streak

Gray

Transparency

Opaque

mineralrare

Niobocarbide

Hardness: 8-9
Luster: Metallic
Streak: Gray
Transparency: Opaque

Is this niobocarbide?

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 niobocarbide with a known reference. Niobocarbide sits at Mohs 8-9 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Niobocarbide leaves a gray streak.
3
Read the luster
Hold the specimen under a strong light. Niobocarbide typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: gray, yellowish-gray.
5
Look at form & habit
Crystal system: cubic. Typical habit: grains.

Often confused with

Niobocarbide vs. its common look-alikes — and how to tell them apart in the field.

mineral

Columbium Ore

Mohs 6

How to tell apart: Niobocarbide is noticeably harder (Mohs 8-9 vs. 6); streak differs — Niobocarbide leaves gray, Columbium Ore leaves dark red to black; luster reads metallic on Niobocarbide and submetallic on Columbium Ore.

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Often found alongside niobocarbide

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

All properties

Chemical formula: NbC
Mohs hardness: 8-9
Density: 7.6-7.8 g/cm³
Colors: Gray Yellowish-gray
Streak: Gray
Luster: Metallic
Transparency: Opaque
Crystal system: Cubic
Crystal habit: Grains
Cleavage: None
Rarity: Rare
Uses: Research, Collector
Host rock: Kimberlite
Typical price: $50-300 per specimen

Where rockhounds find niobocarbide

Classic worldwide localities

Kola Peninsula, Russia
Yakutia, Russia

Field-hunting tip

Look in kimberlite country — that is the host setting where niobocarbide typically forms. If you start seeing diamond, platinum, chromite in float, you are in the right ground. Field specimens usually show a grains habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify niobocarbide?+

Mohs hardness is 8-9. It typically shows a metallic luster. The streak is gray. Common colors include gray, yellowish-gray.

Where is niobocarbide found?+

Notable localities include Kola Peninsula, Russia; Yakutia, Russia.

How much is niobocarbide worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like niobocarbide?+

Niobocarbide is most often confused with Columbium Ore. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with niobocarbide?+

Niobocarbide commonly co-occurs with Diamond, Platinum, Chromite, Olivine. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does niobocarbide form in?+

Niobocarbide typically forms in kimberlite. Working float back to the host body is the standard way to chase a fresh occurrence.

What is niobocarbide used for?+

Niobocarbide is used in research, collector.

Find niobocarbide on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.