Innsbruckite is an extremely rare manganese silicate mineral first identified in the Innsbruck region of Austria. It is typically found as small, tabular monoclinic crystals in metamorphic environments and is primarily valued by advanced mineralogists for its scarcity.

Hardness

Mohs

Transparency

Transparent

mineralrare

Innsbruckite

Hardness: 6
Transparency: Transparent

No image

Is this innsbruckite?

3-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 innsbruckite with a known reference. Innsbruckite sits at Mohs 6, softer than the next harder reference, harder than the previous one.
2
Match the color range
Compare against the expected color range: colorless, white, yellowish.
3
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular crystals.

Often confused with

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

Often found alongside innsbruckite

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

All properties

Chemical formula: Mn₃₃(Si₂O₅)₁₄(OH)₃₈
Mohs hardness: 6
Density: 3.216 g/cm³
Colors: Colorless White Yellowish
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Tabular crystals
Rarity: Rare
Uses: Collector
Host rock: Between serpentinite and chert, related to a late hydration stage after blueschist-facies metamorphism of former Mn-rich marine sediments

Where rockhounds find innsbruckite

Classic worldwide localities

Staffelsee (Geier), Navis valley, 20 km southeast of Innsbruck, Tyrol, Austria

Field-hunting tip

Where it forms: Between serpentinite and chert, related to a late hydration stage after blueschist-facies metamorphism of former Mn-rich marine sediments. If you start seeing rhodochrosite, friedelite, tephroite in float, you are in the right ground. Typical habit: tabular crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify innsbruckite?+

Mohs hardness is 6. Common colors include colorless, white, yellowish.

Where is innsbruckite found?+

Notable localities include Staffelsee (Geier), Navis valley, 20 km southeast of Innsbruck, Tyrol, Austria.

What rocks look like innsbruckite?+

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

What minerals are found with innsbruckite?+

Innsbruckite commonly co-occurs with Rhodochrosite, Friedelite, Tephroite, Spessartine, Calcite, Apatite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does innsbruckite form in?+

Where it forms: Between serpentinite and chert, related to a late hydration stage after blueschist-facies metamorphism of former Mn-rich marine sediments. Working float back to the host body is the standard way to chase a fresh occurrence.

What is innsbruckite used for?+

Innsbruckite is used in collector.

Find innsbruckite on the map

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