Hansesmarkite is a very rare manganese calcium silicate mineral occurring in phosphate-rich granitic pegmatites. It typically forms as delicate, platy crystals or radiating sprays and is primarily valued by advanced micromount collectors due to its extreme scarcity.

Hardness

2-2.5

Mohs

Luster

Vitreous to resinous

Streak

Pale yellow

Transparency

Transparent

mineralrare

Hansesmarkite

Hardness: 2-2.5
Luster: Vitreous to resinous
Streak: Pale yellow
Transparency: Transparent

No image

Is this hansesmarkite?

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 hansesmarkite with a known reference. Hansesmarkite 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. Streak: pale yellow.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous to resinous.
4
Match the color range
Compare against the expected color range: yellow.
5
Look at form & habit
Crystal system: triclinic. Typical habit: platy crystals, radial aggregates.

Often confused with

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

mineral

Lawsonite

Mohs 6

How to tell apart: Lawsonite is the harder of the two (Mohs 6 vs. 2-2.5); streak differs, so Hansesmarkite leaves pale yellow, Lawsonite leaves white.

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Often found alongside hansesmarkite

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

All properties

Chemical formula: Ca₂Mn₂Nb₆O₁₉·20H₂O
Mohs hardness: 2-2.5
Density: 2.74 g/cm³
Colors: Yellow
Streak: Pale yellow
Luster: Vitreous to resinous
Transparency: Transparent
Crystal system: Triclinic
Crystal habit: Platy crystals, radial aggregates
Cleavage: Good on {011} and {011̄}
Rarity: Rare
Uses: Collector
Host rock: On fracture surfaces in a hydrothermally altered syenite pegmatite dike

Where rockhounds find hansesmarkite

Classic worldwide localities

Found at level 4 of the AS Granit larvikite quarry, Tvedalen, Larvik, Vestfold, Norway

Field-hunting tip

Where it forms: On fracture surfaces in a hydrothermally altered syenite pegmatite dike. If you start seeing analcime, arsenopyrite, behoite in float, you are in the right ground. Typical habit: platy crystals, radial aggregates. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify hansesmarkite?+

Mohs hardness is 2-2.5. Luster: vitreous to resinous. The streak is pale yellow. Common colors include yellow.

Where is hansesmarkite found?+

Notable localities include Found at level 4 of the AS Granit larvikite quarry, Tvedalen, Larvik, Vestfold, Norway.

What rocks look like hansesmarkite?+

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

What minerals are found with hansesmarkite?+

Hansesmarkite commonly co-occurs with Analcime, Arsenopyrite, Behoite, Bertrandite, Calcite, Chiavennite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does hansesmarkite form in?+

Where it forms: On fracture surfaces in a hydrothermally altered syenite pegmatite dike. Working float back to the host body is the standard way to chase a fresh occurrence.

What is hansesmarkite used for?+

Hansesmarkite is used in collector.

Find hansesmarkite on the map

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