Rathite is a rare sulfosalt mineral typically found in the famous Binn Valley of Switzerland. Collectors prize it for its complex, metallic-lustered, often deeply striated crystals found within dolomitic marble.

Hardness

Mohs

Luster

Metallic to dull

Streak

Chocolate-brown

Transparency

Opaque

mineralrareSartorite Group family

Rathite

Hardness: 3
Luster: Metallic to dull
Streak: Chocolate-brown
Transparency: Opaque

Is this rathite?

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 rathite with a known reference. Rathite sits at Mohs 3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: chocolate-brown.
3
Read the luster
Hold the specimen under a strong light. Luster: metallic to dull.
4
Match the color range
Compare against the expected color range: lead gray.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: prismatic.

Often confused with

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

How to tell apart: Streak differs, so Rathite leaves chocolate-brown, Dufrénoysite leaves reddish brown to chocolate-brown; luster reads metallic to dull on Rathite and submetallic on Dufrénoysite.

Often found alongside rathite

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

All properties

Chemical formula: Ag₂Pb₁₂-xTlx/2As₁₈+x/2S₄₀; (0 ≤ x ≤ 5)
Mohs hardness: 3
Density: 4.986-5.446 g/cm³
Colors: Lead gray
Streak: Chocolate-brown
Luster: Metallic to dull
Transparency: Opaque
Crystal system: Monoclinic
Crystal habit: Prismatic
Cleavage: Perfect on {001}; parting on {010}
Rarity: Rare
Uses: Collector
Host rock: In crystalline dolostone with other Pb-As-S minerals

Where rockhounds find rathite

Classic worldwide localities

Lengenbach quarry (type locality) and at Reckibach, Binntal, Valais, Switzerland

Field-hunting tip

Where it forms: In crystalline dolostone with other Pb-As-S minerals. If you start seeing liveingite, baumhauerite, sartorite in float, you are in the right ground. Typical habit: prismatic. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify rathite?+

Mohs hardness is 3. Luster: metallic to dull. The streak is chocolate-brown. Common colors include lead gray.

Where is rathite found?+

Notable localities include Lengenbach quarry (type locality) and at Reckibach, Binntal, Valais, Switzerland.

Is rathite safe to handle?+

Rathite contains arsenic, lead and thallium and calls for real care. Contains arsenic and lead. Wash hands thoroughly after handling specimens and avoid inhaling dust.

What rocks look like rathite?+

Rathite is most often confused with Sartorite, Dufrénoysite, Baumhauerite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with rathite?+

Rathite commonly co-occurs with Liveingite, Baumhauerite, Sartorite, Hutchinsonite, Dufrénoysite, Tennantite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does rathite form in?+

Where it forms: In crystalline dolostone with other Pb-As-S minerals. Working float back to the host body is the standard way to chase a fresh occurrence.

What is rathite used for?+

Rathite is used in collector.

Find rathite on the map

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