“The peninsula carved by Time out of a single stone” is how Thomas Hardy famously described the Isle of Portland. In the same novel, The Well-Beloved, he describes it simply as “this stone isle”, where you can always hear “the tink-tink of the chisels in the quarries”.

“…whirr-whirr, saw-saw-saw. Those were the island’s snores—the noises of the quarrymen and stone-sawyers.”

Hardy also refers to Portland, in a geological flourish, as “the oolitic isle”. The word “oolitic” comes from the Greek for “egg-stone” or “roe-stone”, because it resembles fish roe. The Geological Society explains the term:

“Oolitic limestone is made up of small spheres called ooiliths that are stuck together by lime mud. They form when calcium carbonate is deposited on the surface of sand grains rolled (by waves) around on a shallow sea floor.”

Over millions of years, these “ooliths” became slowly cemented together or “lithified” to form the limestone. As Dorset Council, in its overview of the Portland stone industry, says:

“Portland stone is an oolitic limestone that was deposited around 145-163.5 million years ago during the late Jurassic period, when the UK was situated in a more sub-tropical latitude”

Limestone has been mined from Portland since Roman times, and examples of it have been found in excavations of Roman Dorchester. The stone “became quarried on a more industrial scale from the 16th Century” — that’s according to a fascinating article in the journal Urban Geology in London by Gill Hackman and Ruth Siddall:

Portland was, as it is today, a Royal manor, and Portland Stone appears to have been used initially largely to enhance buildings for the Crown or in which the monarch took a particular interest. Inigo Jones was the architect who first brought large quantities of Portland Stone to London…. It was used in Inigo Jones’s Banqueting House on Whitehall in 1622 and the construction of this building started a trend for Portland Stone.”

But the real boom for Portland stone came in the 17th Century. As Natasha Foges writes, in a piece about the stone of the Jurassic Coast for the magazine Britain:

Portland stone was once the unofficial building block of London. Sir Christopher Wren, Member of Parliament for nearby Weymouth, controlled Portland’s quarries and popularised the use of the local stone. After the Great Fire of London in 1666, some 6 million tonnes of it were shipped from Portland to rebuild the capital. Over the years, historic landmarks such as Wren’s St Paul’s Cathedral, the British Museum and Buckingham Palace were made from this distinctive pale limestone.

The physical qualities of Portland stone, says architecture expert Clive Aslet, made it peculiarly suited to life in London, as “it could withstand the pollution”, and was “washed ghostly white by the rain”.

In 2013, the archeologist Julian Richards made a film about how the Victorians got stone from the island’s quarries down to sea level, and you can watch a Pathé News film about Portland stone industry from 1955 here. And you can find images from the history of the Portland stone industry at Portland Museum’s stone exhibit.

There’s a useful overview of Portland’s geology and mining industry in Portland’s Quarries and its Stone by Mark Godden of Albion Stone, which shows the stratification of the island and explains how the rocks are quarried and cut. And for a more detailed look at the unique geology of Portland there’s this in depth study by Ian West, written while he was a Visiting Scientist at the Faculty of Natural and Environmental Science, Southhampton University.

Chesil Beach

Even though Portland is “internationally important for its geological interest” it is perhaps less famous than its north-eastern neighbour, Chesil Beach.

Technically, Portland is a “tied island”, connected to the mainland by the world’s most famous “tombolo”. The term is explained in the Heights Hotel guide to the island as “a spit joined to land at both ends”. From its beginning at Portland, the tombolo “runs 29 kilometres (18miles) north-west to West Bay.”

Chesil Beach is described by Brian Jackman in the Daily Telegraph as “one of the geological wonders of the world, a giant bank of sea-heaped pebbles”. You can find an overview of the geology of Chesil Beach by Dr. James B. Calvert of Denver University here.

More information on the Jurassic Coast as a World Heritage Site here.