Phosgenite is a rare lead chloride carbonate typically found as a secondary mineral in oxidized lead deposits. It is highly prized by collectors for its brilliant adamantine luster and distinct tetragonal prismatic crystal habit, which often fluoresce a characteristic bright yellow under UV light.

Hardness

2.5-3

Mohs

Luster

Adamantine

Streak

White

Transparency

Transparent

mineralrare

Phosgenite

Also: Cromfordite

Hardness: 2.5-3
Luster: Adamantine
Streak: White
Transparency: Transparent

Is this phosgenite?

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 phosgenite with a known reference. Phosgenite sits at Mohs 2.5-3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Phosgenite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Phosgenite typically shows a adamantine luster.
4
Match the color range
Compare against the expected color range: colorless, white, gray, yellow.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: prismatic crystals, tabular.

Often confused with

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

Often found alongside phosgenite

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

All properties

Chemical formula: Pb₂Cl₂CO₃
Mohs hardness: 2.5-3
Density: 6.1-6.3 g/cm³
Colors: Colorless White Gray Yellow
Streak: White
Luster: Adamantine
Transparency: Transparent
Crystal system: Tetragonal
Crystal habit: Prismatic Crystals, Tabular
Cleavage: Distinct On {110}
Fluorescence: Bright Yellow Under SW and LW UV
Rarity: Rare
Uses: Collector
Host rock: Oxidized Lead Deposits
Typical price: $50-500 thumbnail

Where rockhounds find phosgenite

Classic worldwide localities

Cromford, England
Monteponi, Sardinia
Broken Hill, Australia
Touissit, Morocco

Field-hunting tip

Look in oxidized lead deposits country, the host setting where phosgenite typically forms. If you start seeing cerussite, anglesite, galena in float, you are in the right ground. Field specimens usually show a prismatic crystals, tabular habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify phosgenite?+

Mohs hardness is 2.5-3. It typically shows a adamantine luster. The streak is white. Common colors include colorless, white, gray, yellow.

Where is phosgenite found?+

Notable localities include Cromford, England; Monteponi, Sardinia; Broken Hill, Australia; Touissit, Morocco.

How much is phosgenite worth?+

Typical asking prices fall in the range of $50-500 thumbnail. Quality, size, and provenance can move individual specimens well outside that range.

Is phosgenite safe to handle?+

It contains toxic constituents. Contains lead, which is toxic. Handle with care, wash hands after touching, and do not ingest or inhale dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like phosgenite?+

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

What minerals are found with phosgenite?+

Phosgenite commonly co-occurs with Cerussite, Anglesite, Galena, Hydrocerussite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does phosgenite form in?+

Phosgenite typically forms in oxidized lead deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is phosgenite used for?+

Phosgenite is used in collector.

Find phosgenite on the map

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