Brownleeite is an extremely rare manganese-silver-arsenic sulfosalt mineral primarily known from its type locality at the Brownlee Mine in Idaho. It is typically found as microscopic grains embedded within complex hydrothermal sulfide ores and is highly sought after by advanced mineral collectors.

Hardness

3.5-4

Mohs

Luster

Metallic

Streak

Yellow

Transparency

Opaque

mineralrare

Brownleeite

Hardness: 3.5-4
Luster: Metallic
Streak: Yellow
Transparency: Opaque

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Is this brownleeite?

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 brownleeite with a known reference. Brownleeite sits at Mohs 3.5-4 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Brownleeite leaves a yellow streak.
3
Read the luster
Hold the specimen under a strong light. Brownleeite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: yellow, brownish-yellow.
5
Look at form & habit
Crystal system: cubic. Typical habit: anhedral grains.

Often confused with

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

mineral

Sphalerite

Mohs 3.5-4

How to tell apart: Streak differs — Brownleeite leaves yellow, Sphalerite leaves white to yellow-brown; luster reads metallic on Brownleeite and resinous to submetallic on Sphalerite.

How to tell apart: Streak differs — Brownleeite leaves yellow, Stannite leaves black.

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Often found alongside brownleeite

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

All properties

Chemical formula: MnAgAsS₃
Mohs hardness: 3.5-4
Density: 4.8 g/cm³
Colors: Yellow Brownish-yellow
Streak: Yellow
Luster: Metallic
Transparency: Opaque
Crystal system: Cubic
Crystal habit: Anhedral Grains
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins
Typical price: $100-500 thumbnail

Where rockhounds find brownleeite

Classic worldwide localities

Brownlee Mine, Idaho, USA

Field-hunting tip

Look in hydrothermal veins country — that is the host setting where brownleeite typically forms. If you start seeing galena, sphalerite, chalcopyrite in float, you are in the right ground. Field specimens usually show a anhedral grains habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify brownleeite?+

Mohs hardness is 3.5-4. It typically shows a metallic luster. The streak is yellow. Common colors include yellow, brownish-yellow.

Where is brownleeite found?+

Notable localities include Brownlee Mine, Idaho, USA.

How much is brownleeite worth?+

Typical asking prices fall in the range of $100-500 thumbnail. Quality, size, and provenance can move individual specimens well outside that range.

Is brownleeite safe to handle?+

It contains toxic constituents. Contains arsenic, which is toxic; handle with care and wash hands after handling to avoid ingestion or inhalation of dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like brownleeite?+

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

What minerals are found with brownleeite?+

Brownleeite commonly co-occurs with galena, sphalerite, chalcopyrite, arsenopyrite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does brownleeite form in?+

Brownleeite typically forms in hydrothermal veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is brownleeite used for?+

Brownleeite is used in collector.

Find brownleeite on the map

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