Minerals and mines

Introduction | History of lead mining | History of zinc mining | Lead ore & mines
Zinc ore & mines | Iron ore, ochre & mines | Coal mining


There has been a long history of mining on the Mendip Hills stretching back over 2000 years to Iron Age times.

Many minerals have been won from the region, but the most common were the ores of lead, zinc and iron. It has been estimated that about 100 000 tons of lead have been obtained from the Mendips. Small amounts of manganese, silver (associated with lead ore), barium and strontium have also been worked. In East Mendip, there are relatively few mineral deposits, but here coal mining was once an important industry.

There must be literally thousands of mines scattered across the Mendip Hills, most of which remain unexplored. Most of the known mines are small, up to 40 m deep and generally less than 100 m long, but a few of the larger mines have several hundred metres of passage. Not all the mines produced ore, many were exploratory shafts sunk along calcite veins in the hope of fining richer ore bodies.

Most of the lead ore came from the central Mendip region between Charterhouse and Green Ore, whereas most of the zinc was obtained from the region around Shipham and Rowberrow. Smaller ore fields occurred as far afield as Banwell and Shepton Mallet. The region was divided into four mining districts known as ‘liberties’ at Priddy, Chewton, Charterhouse and Harptree. Today, there are no active mines. Instead, the most valuable mineral is the rock itself.

Gangue minerals
Calcite CaCO3 A very common mineral the main constituent of limestone.
Aragonite CaCO3 A polymorph * of calcite
Dolomite (MgCa)CO3 A common sedimentary rock-forming mineral, the main constituent of the rock dolomite
Barytes BaSO4 A common, heavy, yellow mineral
Lead minerals
Galena PbS A distinctive heavy, shiny, lead ore.
Cerrusite PbCO3 A secondary white, lead carbonate mineral, formed by alteration or weathering of a primary mineral
Pyromorphite Pb5(PO4,AsO4)3,Cl A green lead ore occasionally found on Mendip
Zinc minerals
Sphalerite ZnS A grey metallic zinc sulphide mineral
Smithsonite ZnCO3 A secondary mineral and the main zinc ore, formed by alteration or weathering of a primary mineral.
Iron minerals
Goethite FeO,OH A complex dirty iron ore
Haematite Fe2O3 Common iron ore, blood red when powdered
Limonite FeO,OH A mixture or iron oxide minerals
Ochre FeO,OH A mixture or iron oxide minerals
Iron pyrite FeS2 Also known as fool's gold
Manganese minerals
Pyrolusite MnO2 Also known as Wad