Sursassite is a rare manganese aluminum silicate typically found as reddish-brown fibrous or radiating needle-like crystals. It is most commonly identified in manganese-rich metamorphic deposits, often associated with braunite and quartz. Collectors usually seek it out as micro-specimens from its type locality in the Swiss Alps.

Hardness

6.5-7

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrarePumpellyite Group family

Sursassite

Hardness: 6.5-7
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this sursassite?

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 sursassite with a known reference. Sursassite sits at Mohs 6.5-7 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Sursassite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Sursassite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: reddish-brown, brown.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: fibrous, radiating aggregates, massive.

Often confused with

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

Often found alongside sursassite

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

All properties

Chemical formula: Mn²⁺₂Al₃(Si₂O₇)(SiO₄)O(OH)₃
Mohs hardness: 6.5-7
Density: 3.37 g/cm³
Colors: Reddish-brown Brown
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Fibrous, Radiating Aggregates, Massive
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Manganiferous Metamorphic Rocks
Typical price: $20-150 for thumbnail specimens

Where rockhounds find sursassite

Classic worldwide localities

Graubünden, Switzerland
Val d'Err, Switzerland
Ogliastra, Italy

Field-hunting tip

Look in manganiferous metamorphic rocks country — that is the host setting where sursassite typically forms. If you start seeing quartz, braunite, tansanite in float, you are in the right ground. Field specimens usually show a fibrous, radiating aggregates, massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify sursassite?+

Mohs hardness is 6.5-7. It typically shows a vitreous luster. The streak is white. Common colors include reddish-brown, brown.

Where is sursassite found?+

Notable localities include Graubünden, Switzerland; Val d'Err, Switzerland; Ogliastra, Italy.

How much is sursassite worth?+

Typical asking prices fall in the range of $20-150 for thumbnail specimens. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like sursassite?+

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

What minerals are found with sursassite?+

Sursassite commonly co-occurs with Quartz, Braunite, Tansanite, Hollandite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does sursassite form in?+

Sursassite typically forms in manganiferous metamorphic rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is sursassite used for?+

Sursassite is used in collector.

Find sursassite on the map

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