Muirshiel Barytes Mine

Overview

A remote Renfrewshire barytes mine worked on and off for around 200 years, which at its peak in the 1950s and 60s supplied roughly a third of the UK's entire barytes output.

History

Small-scale opencast working of baryte (barium sulphate) began high in the moorland above Lochwinnoch around the mid-18th century, with horizontal adits later cut to follow the mineral seams underground. Recorded production between 1859 and 1920 totalled 17,678 long tons, after which the mine fell idle until it was reopened in 1942 by Messrs Keir and Cawder Ltd together with Messrs James Millar Son and Co Ltd. The Muirshiel Barytes Company was formed in 1947 and sank new shafts, and Rio Tinto Zinc took over as operator in 1962. Output peaked in 1964, by which point Muirshiel's roughly 20,000 tons a year, together with Scotland's other barytes mines, accounted for around a third of total UK production. The mine finally closed in September 1969 after about two centuries of intermittent working. Barytes mining here was genuinely dangerous work: many men were killed or badly injured over the mine's life by rock falls, accidents involving explosives, and accidents travelling to and from the remote site, though no single incident is recorded in detail as a discrete disaster.

Geology

Muirshiel worked baryte veins in the moorland uplands of what is now Clyde Muirshiel Regional Park, Renfrewshire.

Workings

Baryte was worked first by small-scale opencast pits, later by horizontal adits driven to follow the mineral seams, and eventually by shafts sunk from 1947 onward.

Closure

The mine closed in September 1969, having been worked intermittently for roughly 200 years; its deep shafts have since been safely capped.

What remains

A few surface buildings and areas of opencast working survive within Clyde Muirshiel Regional Park; the deep shafts are safely capped.

Surface buildings, opencast workings and capped shaft sites, now within a public regional park.

Abandoned workings can be dangerous — unstable ground, uncapped shafts, flooding and bad air are common even where a site looks safe from the surface. This entry describes history and general location only; it is not an access guide.

Recorded claims

Individual factual claims, each attached to the source(s) that support it below. Where sources disagree, both are kept.

• Small-scale opencast baryte working began around the mid-18th century, with recorded production of 17,678 long tons between 1859 and 1920 before the mine fell idle and was later reopened in 1942. ¹
• Output peaked in 1964 at around 20,000 tons a year, with Muirshiel and Scotland's other barytes mines together accounting for roughly a third of total UK barytes production. ¹
• The mine closed in September 1969 after around 200 years of intermittent working. ^1,2
• Barytes mining at Muirshiel was dangerous work, with many men killed or badly injured over the mine's life by rock falls, accidents with explosives, and accidents travelling to and from the remote site, though no single incident is documented in enough detail to stand as a discrete disaster record. (uncertain) ¹

Sources

1. (primary) Muirshiel Barytes Mine in Clyde Muirshiel Regional Park — Clyde Muirshiel Regional Park
2. (secondary) Muirshiel Barytes Mine — Wikipedia

Record created: 21 August 2026 · Last researched: 21 August 2026