Pyrosmalite-(Fe) is a rare manganese-iron silicate typically found in skarn environments. Collectors prize it for its distinct, mica-like pearly luster on its perfect cleavage planes and its characteristic tabular hexagonal crystal habit.

Hardness

4.5

Mohs

Luster

Pearly

Streak

Pale Yellow

Transparency

Translucent

mineralrarePyrosmalite Group family

Pyrosmalite-(Fe)

Hardness: 4.5
Luster: Pearly
Streak: Pale Yellow
Transparency: Translucent

Is this pyrosmalite-(fe)?

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 pyrosmalite-(fe) with a known reference. Pyrosmalite-(Fe) sits at Mohs 4.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Pyrosmalite-(Fe) leaves a pale yellow streak.
3
Read the luster
Hold the specimen under a strong light. Pyrosmalite-(Fe) typically shows a pearly luster.
4
Match the color range
Compare against the expected color range: brown, dark brown, yellowish-brown, olive-green.
5
Look at form & habit
Crystal system: trigonal. Typical habit: tabular crystals, hexagonal prisms, massive.

Often confused with

Pyrosmalite-(Fe) vs. its common look-alikes — and how to tell them apart in the field.

mineral

Biotite

Mohs 2.5-3

How to tell apart: Pyrosmalite-(Fe) is noticeably harder (Mohs 4.5 vs. 2.5-3); streak differs — Pyrosmalite-(Fe) leaves pale yellow, Biotite leaves white.

How to tell apart: Pyrosmalite-(Fe) is noticeably harder (Mohs 4.5 vs. 2.5-3); streak differs — Pyrosmalite-(Fe) leaves pale yellow, Phlogopite leaves white.

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Often found alongside pyrosmalite-(fe)

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

All properties

Chemical formula: (Fe,Mn)₈Si₆O₁₅(OH,Cl)₁₀
Mohs hardness: 4.5
Density: 3.1-3.2 g/cm³
Colors: Brown Dark Brown Yellowish-brown Olive-green
Streak: Pale Yellow
Luster: Pearly
Transparency: Translucent
Crystal system: Trigonal
Crystal habit: Tabular Crystals, Hexagonal Prisms, Massive
Cleavage: Perfect Basal
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Metasomatic Deposits
Typical price: $20-200 depending on specimen size and clarity

Where rockhounds find pyrosmalite-(fe)

Classic worldwide localities

Nordmark, Sweden
Långban, Sweden
Franklin, New Jersey, USA
Broken Hill, Australia

Field-hunting tip

Look in hydrothermal metasomatic deposits country — that is the host setting where pyrosmalite-(fe) typically forms. If you start seeing magnetite, andradite, calcite in float, you are in the right ground. Field specimens usually show a tabular crystals, hexagonal prisms, massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify pyrosmalite-(fe)?+

Mohs hardness is 4.5. It typically shows a pearly luster. The streak is pale yellow. Common colors include brown, dark brown, yellowish-brown, olive-green.

Where is pyrosmalite-(fe) found?+

Notable localities include Nordmark, Sweden; Långban, Sweden; Franklin, New Jersey, USA; Broken Hill, Australia.

How much is pyrosmalite-(fe) worth?+

Typical asking prices fall in the range of $20-200 depending on specimen size and clarity. Quality, size, and provenance can move individual specimens well outside that range.

Is pyrosmalite-(fe) safe to handle?+

It contains toxic constituents. Contains chlorine and potential manganese/iron dust inhalation hazards; handle with care and wash hands after contact. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like pyrosmalite-(fe)?+

Pyrosmalite-(Fe) is most often confused with Biotite, Phlogopite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with pyrosmalite-(fe)?+

Pyrosmalite-(Fe) commonly co-occurs with Magnetite, Andradite, Calcite, Fluorite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does pyrosmalite-(fe) form in?+

Pyrosmalite-(Fe) typically forms in hydrothermal metasomatic deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is pyrosmalite-(fe) used for?+

Pyrosmalite-(Fe) is used in collector.

Find pyrosmalite-(fe) on the map

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