White Lias walling
Twerton Mill white Lias

White Lias stone

White lias is a rare and very fine grained form of hard limestone, found almost exclusively in Somerset and occasionally in Warwickshire. It has pastel hues ranging from cream and white to pale greys. While it has been a traditional building stone in the South West, it can be found in stately homes and places of worship across the UK.

The stone itself was formed in the late Triassic period and is more than 205 million years old. A substantial layer is visible at Pinhay Bay near Lyme Regis and its more modern application can be seen in the curbstones of Pound Street in the town. Formed of shale and limestone, the basis of the rock is a bone bed of ancient fossils; these fossils include Aragonitic Bivalvia (marine and fresh water molluscs in hinged shells such as clams, oysters and mussels), gastropods (invertebrates such as snails and slugs) and ammonites.

White lias is particularly favoured by stonemasons such as those here at Ashen Cross Quarry. It is a durable stone but it is also very easy to carve. When quarried the rock has a naturally square form and, even when it is split using traditional methods, tends to retain this shape. Thus it an easy choice for use in both building stones and in landscaping. It is also an excellent medium for flooring with its fine grain texture and warm tones adding an air of refinement to any space.