Somersetite is an extremely rare lead carbonate mineral first discovered in the Mendip Hills of England. It typically forms as small, colorless to white tabular crystals in cavities of oxidized lead-bearing ores. Collectors value it highly due to its rarity and specific type locality association.

Hardness

Mohs

Luster

Adamantine

Streak

White

Transparency

Transparent

mineralrare

Somersetite

Hardness: ~3
Luster: Adamantine
Streak: White
Transparency: Transparent

No image

Is this somersetite?

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 somersetite with a known reference. Somersetite 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: white.
3
Read the luster
Hold the specimen under a strong light. Luster: adamantine.
4
Match the color range
Compare against the expected color range: white, green.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: tabular crystals.

Often confused with

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

Often found alongside somersetite

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

All properties

Chemical formula: Pb₈O(OH)₄(CO₃)₅
Mohs hardness: ~3
Density: 7.01 g/cm³
Colors: White Green
Streak: White
Luster: Adamantine
Transparency: Transparent
Crystal system: Hexagonal
Crystal habit: Tabular crystals
Cleavage: Perfect on {0001}
Rarity: Rare
Uses: Collector
Host rock: In hydrothermal veins of remobilized components derived from older veins containing galena, fluorite, calcite and baryte, hosted by limestone

Where rockhounds find somersetite

Classic worldwide localities

Torr Works quarry (‘Merehead quarry’), near Cranmore, Mendip Hills, Somerset, England

Field-hunting tip

Where it forms: In hydrothermal veins of remobilized components derived from older veins containing galena, fluorite, calcite and baryte, hosted by limestone. If you start seeing plumbonacrite, cerussite, symesite in float, you are in the right ground. Typical habit: tabular crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify somersetite?+

Mohs hardness is ~3. Luster: adamantine. The streak is white. Common colors include white, green.

Where is somersetite found?+

Notable localities include Torr Works quarry (‘Merehead quarry’), near Cranmore, Mendip Hills, Somerset, England.

Is somersetite safe to handle?+

Somersetite contains lead. Contains lead, which is toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and do not grind or ingest.

What rocks look like somersetite?+

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

What minerals are found with somersetite?+

Somersetite commonly co-occurs with Plumbonacrite, Cerussite, Symesite, Mereheadite, Diaboleite, Mimetite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does somersetite form in?+

Where it forms: In hydrothermal veins of remobilized components derived from older veins containing galena, fluorite, calcite and baryte, hosted by limestone. Working float back to the host body is the standard way to chase a fresh occurrence.

What is somersetite used for?+

Somersetite is used in collector.

Find somersetite on the map

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