Peterandresenite is a rare manganese niobium oxide, typically orange. It was approved as a distinct mineral species in 2012. It was first described from AS Granit larvikite, Tvedalen, Larvik, Vestfold, Norway.

Hardness

2-2.5

Mohs

Luster

Vitreous to Resinous

Streak

Pale Orange

Transparency

Transparent

mineralrare

Peterandresenite

Hardness: 2-2.5
Luster: Vitreous to Resinous
Streak: Pale Orange
Transparency: Transparent

Is this peterandresenite?

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 peterandresenite with a known reference. Peterandresenite sits at Mohs 2-2.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Peterandresenite leaves a pale orange streak.
3
Read the luster
Hold the specimen under a strong light. Peterandresenite typically shows a vitreous to resinous luster.
4
Match the color range
Compare against the expected color range: orange.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: platy crystals.

Often confused with

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

mineral

Manganberzeliite

Mohs 5

How to tell apart: Manganberzeliite is the harder of the two (Mohs 5 vs. 2-2.5); streak differs, so Peterandresenite leaves pale orange, Manganberzeliite leaves white; luster reads vitreous to resinous on Peterandresenite and resinous on Manganberzeliite.

Compare →

Often found alongside peterandresenite

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

All properties

Chemical formula: Mn₄Nb₆O₁₉(H₂O)₁₂·2H₂O
Mohs hardness: 2-2.5
Density: 3.10 g/cm³
Colors: Orange
Streak: Pale Orange
Luster: Vitreous to Resinous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Platy Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Metamorphic Manganese Deposits

Where rockhounds find peterandresenite

Classic worldwide localities

AS Granit larvikite, Vestfold, Norway

Field-hunting tip

Look in metamorphic manganese deposits country, the host setting where peterandresenite typically forms. If you start seeing manganberzeliite, hausmannite, calcite in float, you are in the right ground. Field specimens usually show a platy crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify peterandresenite?+

Mohs hardness is 2-2.5. It typically shows a vitreous to resinous luster. The streak is pale orange. Common colors include orange.

Where is peterandresenite found?+

Notable localities include AS Granit larvikite, Vestfold, Norway.

What rocks look like peterandresenite?+

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

What minerals are found with peterandresenite?+

Peterandresenite commonly co-occurs with Manganberzeliite, Hausmannite, Calcite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does peterandresenite form in?+

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

What is peterandresenite used for?+

Peterandresenite is used in collector.

Find peterandresenite on the map

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