Gypsum

A soft sulphate mineral formed by the evaporation of ancient seawater; its finest, translucent form, alabaster, was long prized for sculpture, while coarser gypsum is calcined into plaster of Paris or used directly in cement.

Historical usage

Gypsum and its alabaster variety have been worked since antiquity — ancient Egyptians used it to plaster mud-brick walls and to build the pyramids. In England, Chellaston in Derbyshire became the principal source of medieval alabaster, supplying the Nottingham carving workshops whose devotional sculptures were exported across Europe at their 1360-1460 peak, a trade largely destroyed by the 1550 Act removing Catholic imagery from churches. Plain gypsum extraction at Chellaston continued long after, finally ceasing in 1978.

How it worked

Alabaster, gypsum's finest translucent form, could be carved directly with simple tools; coarser gypsum is calcined — heated to drive off water — to make plaster of Paris, or ground and added to cement to slow its setting time.

Why it was used

Alabaster's softness let it be carved quickly and cheaply into detailed devotional figures, fuelling the medieval English sculpture export trade. Calcined gypsum's fast-setting, low-shrinkage properties make it ideal for casting moulds and ornamental plasterwork, and mixing it into cement controls how quickly the cement sets and hardens.

Value over time

Alabaster's value swung entirely with religious fashion: prized and exported across Europe at its medieval peak, the trade collapsed after the 1550 Act stripped Catholic imagery from English churches, saw a modest Victorian revival, then declined for good after the Second World War as good-quality stone grew scarce. Plain gypsum, valued for cement and plaster rather than carving, kept Chellaston's pits working long after the alabaster trade ended, closing only in 1978.

Hazards & challenges

Gypsum dust is a mild respiratory irritant rather than a major occupational hazard in its own right, though gypsum-based plasterboard work carries a distinct modern risk where the dust contains asbestos fibres from other building materials rather than the gypsum itself.

Risks & limitations

Alabaster's whole medieval market depended on demand for Catholic devotional imagery, which made it acutely vulnerable to the 1550 Act removing such imagery from English churches — a single piece of legislation collapsed the trade almost overnight, something a purely secular building material would not have faced.

Regional variation

Chellaston in Derbyshire and Tutbury in Staffordshire were medieval England's two principal alabaster sources, though Chellaston supplied the larger share of the stone sent to Nottingham's carving workshops.

Images

Mines associated with this term

Included only where MineArchive's own research gives a reasonable evidential basis — not every mine where this might plausibly apply.

• Chellaston Alabaster Mines — Derbyshire (well documented example)
  Medieval England's principal source of alabaster and, later, plain gypsum, worked from the 14th century to 1978.

Sources

1. (secondary) Nottingham alabaster — Wikipedia
2. (secondary) What is Gypsum Used For? Dangers in Construction — High Speed Training

Record created: 22 August 2026 · Last researched: 22 August 2026