Laphamite is a rare arsenic selenide mineral primarily found as a sublimation product in burning coal mine dumps. It is easily identified by its distinctive red platy crystals or coatings which are formed by the condensation of gases near active vents.

Hardness

1.5-2

Mohs

Luster

Resinous

Streak

Orange-red

Transparency

Translucent

mineralrareOrpiment Group family

Laphamite

Hardness: 1.5-2
Luster: Resinous
Streak: Orange-red
Transparency: Translucent

Is this laphamite?

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 laphamite with a known reference. Laphamite sits at Mohs 1.5-2 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Laphamite leaves a orange-red streak.
3
Read the luster
Hold the specimen under a strong light. Laphamite typically shows a resinous luster.
4
Match the color range
Compare against the expected color range: red, orange-red.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: platy crystals, crusts, coatings.

Often confused with

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

mineral

Orpiment

Mohs 1.5-2

How to tell apart: Streak differs — Laphamite leaves orange-red, Orpiment leaves yellow.

Often found alongside laphamite

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

All properties

Chemical formula: As₂Se₃
Mohs hardness: 1.5-2
Density: 3.52 g/cm³
Colors: Red Orange-red
Streak: Orange-red
Luster: Resinous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Platy Crystals, Crusts, Coatings
Cleavage: Perfect in One Direction
Rarity: Rare
Uses: Collector
Host rock: Burning Coal Mine Waste Dumps
Typical price: $50-300 per specimen depending on size and quality

Where rockhounds find laphamite

Classic worldwide localities

Centralia, Pennsylvania (USA)

Field-hunting tip

Look in burning coal mine waste dumps country — that is the host setting where laphamite typically forms. If you start seeing sulfur, ammonia-alum, realgar in float, you are in the right ground. Field specimens usually show a platy crystals, crusts, coatings habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify laphamite?+

Mohs hardness is 1.5-2. It typically shows a resinous luster. The streak is orange-red. Common colors include red, orange-red.

Where is laphamite found?+

Notable localities include Centralia, Pennsylvania (USA).

How much is laphamite worth?+

Typical asking prices fall in the range of $50-300 per specimen depending on size and quality. Quality, size, and provenance can move individual specimens well outside that range.

Is laphamite safe to handle?+

It contains toxic constituents. Contains arsenic and selenium; wash hands thoroughly after handling and avoid inhaling dust or fumes if heated. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like laphamite?+

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

What minerals are found with laphamite?+

Laphamite commonly co-occurs with Sulfur, Ammonia-alum, Realgar. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does laphamite form in?+

Laphamite typically forms in burning coal mine waste dumps. Working float back to the host body is the standard way to chase a fresh occurrence.

What is laphamite used for?+

Laphamite is used in collector.

Find laphamite on the map

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