Katoptrite is a very rare manganese-antimony mineral primarily found in the metamorphosed iron-manganese deposits of Sweden. It typically appears as black, tabular, metallic-lustered crystals associated with other rare manganese minerals in skarn-like environments.

Hardness

5-6

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrarenull family

Katoptrite

Hardness: 5-6
Luster: Metallic
Streak: Black
Transparency: Opaque

Is this katoptrite?

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 katoptrite with a known reference. Katoptrite sits at Mohs 5-6 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Katoptrite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Katoptrite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: black.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular crystals, massive.

Often confused with

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

How to tell apart: Streak differs — Katoptrite leaves black, Hausmannite leaves brownish-red; luster reads metallic on Katoptrite and submetallic on Hausmannite.

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Often found alongside katoptrite

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

All properties

Chemical formula: (Mn,Mg)₁₄Sb₂Zn₂Si₂O₂₇
Mohs hardness: 5-6
Density: 4.95 g/cm³
Colors: Black
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Monoclinic
Crystal habit: Tabular Crystals, Massive
Cleavage: Perfect Basal
Rarity: Rare
Uses: Collector
Host rock: Metamorphosed Manganese Ore Deposits
Typical price: $50-500 depending on specimen size and clarity

Where rockhounds find katoptrite

Classic worldwide localities

Nordmark, Sweden
Langban, Sweden

Field-hunting tip

Look in metamorphosed manganese ore deposits country — that is the host setting where katoptrite typically forms. If you start seeing magnetite, hausmannite, beryllite in float, you are in the right ground. Field specimens usually show a tabular crystals, massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify katoptrite?+

Mohs hardness is 5-6. It typically shows a metallic luster. The streak is black. Common colors include black.

Where is katoptrite found?+

Notable localities include Nordmark, Sweden; Langban, Sweden.

How much is katoptrite worth?+

Typical asking prices fall in the range of $50-500 depending on specimen size and clarity. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like katoptrite?+

Katoptrite is most often confused with Magnetite, Hausmannite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with katoptrite?+

Katoptrite commonly co-occurs with Magnetite, Hausmannite, Beryllite, Allactite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does katoptrite form in?+

Katoptrite typically forms in metamorphosed manganese ore deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is katoptrite used for?+

Katoptrite is used in collector.

Find katoptrite on the map

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