Hearthstone

A soft, calcareous variety of Reigate Stone from the Upper Greensand, used from the Victorian era into the 1960s for whitening doorsteps, stone floors and hearths.

Historical usage

Hearthstone is the softest, most friable variety of the Reigate Stone worked underground at Merstham and neighbouring sites in east Surrey, interbedded with the harder Firestone. A Victorian fashion for scrubbed white doorsteps created enormous demand for it from the 19th century onward, and hearthstone production remained in popular use right through the Second World War; by the trade's final years it was the only product these ancient underground stone mines still worked, an activity that only finally ceased in the 1960s.

How it worked

Like Firestone, hearthstone was mined underground in lumps with hammers and wedges along the rock's natural joints. In use, a lump was wetted and rubbed directly onto a stone step or hearth, leaving behind a white, chalky deposit that brightened the surface.

Why it was used

Its softness and fine, calcareous texture, useless for ordinary building work, were exactly what made it effective as a domestic whitening agent, rubbed onto doorsteps and hearths to keep them looking clean.

Risks & limitations

A material valuable only for a narrow domestic use rather than structural building work, hearthstone's market shrank along with the Victorian and early 20th-century fashion for whitened stone surfaces that had created it.

Regional variation

A Surrey trade name for this Reigate Stone variety; the underlying practice of whitening steps with a soft local stone was not unique to Surrey, though this particular material and name are.

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.

• Merstham Chalk Mines — Surrey (well documented example)
  Named twice in this record, first in the history: “…Merstham declined, reviving only on a smaller scale as a source of hearthstone, used for whitening doorsteps, stone floors and hearths. In July…”
• Reigate Caves — Surrey (well documented example)
  Named in this record’s closure notes: “…East Surrey stone industry outlasted it: mine plans for the Reigate hearthstone workings record abandonment in 1961, and the last Reigate stone mine…”

Sources

1. (secondary) History of Merstham — Reigate and Redhill Society
2. (secondary) The Exploitation, Distribution and Use in Buildings of Reigate Stone pt1 — Croydon Caving Club

Record created: 27 August 2026 · Last researched: 27 August 2026