Sisapo

About

Pliny called this the empire's most valuable mine for the revenue it brought the treasury, and its cinnabar ore supplied nearly all the vermilion pigment used to redden Roman walls, cosmetics, and ceremonial togas. A leasing company called the societas sisaponensis ran the works on the state's behalf. The deposit here remains the largest mercury reserve ever found on Earth.

What happened here

Work goes on underground by lamplight in shifts, and the lamp is also the clock. Galleries follow the ore, propped with timber, drained by wooden screws and bucket wheels worked by hand in stages up the shaft. Ventilation is a second shaft and a fire to draw the air. The labour is convicts, slaves and paid men working side by side on different terms, and the paid men do the skilled cutting. Above ground the ore is crushed, washed in long channels, and smelted, and the smoke kills the vegetation for miles. Mines of any size are imperial property, leased to contractors under written regulations covering shifts, drainage, bath-house charges and who may open a new gallery. Settlements grow around them fast and empty just as fast.

In ancient writing

• Pliny the Elder, Natural History 33.118–122

  Cinnabar from Sisapo is a state monopoly: the ore is sealed at the mine, refined only at Rome, and the price is fixed by law to stop adulteration.

Sources

• Pliny the Elder, Natural History 33.118
• https://fundacionpalarq.com/en/what-is-cinnabar-the-pigment-of-roman-mural-painting/