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

mineralrare

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, so 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, 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.