Matter of Time
An epic journey underground and back in time, we discover the future of the famous Portland stone.

The Isle of Portland is one giant hunk of rock rising out of the Atlantic. Today, its top is shrouded in sea mist, and a town of grey and white terraces clambers up in steep steps until they too disappear. Driving along Chesil Beach – a six-storeys-high, twenty-mile-long bank of shingle that connects the island to the rest of Dorset – we’re in search of London’s most highly prized stone. Whitehall, Buckingham Palace, the Bank of England, St Paul’s Cathedral – government, sovereignty, economy and religion – they all chose Portland. But we’re finding out how St James’s Market is showing London a completely new side to this treasured material.

Portland is a story set in stone: beautiful, pale, off-white stone. With its 2,000 years of quarrying, it charts environmental change, industrial innovation and matters of taste.

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It all begins 150 million years ago. A time when Britain looked like Barbados. Portland, in particular, was a landscape of tropical lagoons, its warm seas inhabited by marine crocodiles with metre-long jaws and three-toed wading dinosaurs.

Its warm, salty, shallow seabeds created the perfect conditions for limestone. “Much like the limescale in your kettle,” Quarry and Mine Manager Mark Godden neatly describes the slow, unique chemical build up of Portland’s stone layers. With encapsulated crustaceans like oysters and fossilised palms, each is a snapshot of life at the time. 

Godden points out these distinctive Portland layers. Overburden to Roach
to Whitbed to Bedrock – each has it own distinctive qualities: “Architects choose stone like people choose wallpaper.” Though Portland Stone clearly has favourable construction qualities – structurally sound, weather resistant to 2mm per hundred years, etc – Godden is particularly pleased with the choices made by Make Architects on St James’s Market.

With over 2,000 individual pieces of stone, St James’ Market is its own cliff face. Sourced from across unusual layers and quarries, the stone panels cover a spectrum of tone, texture and, well, shelliness – from the consistency of cream of chicken soup with cracked black pepper, moving through to a more tumultuous porridge, all the way to fibrous flapjack flecked with ancient ammonites and shell shards that polish up like mother of pearl. The Portland Stone facades at St James’s Market read like a tapestry dedicated to the beauty of Jurassic Britain.

Up in the clouds, examining the samples laid out for quality control in the front yard, you can fully appreciate the beautiful quirks of this natural wallpaper. The odd dark seam of fossilised sponges laid down by a hurricane, or an immaculately preserved turtle – the latter discovered by Godden’s wife one morning’s visit: “she’ll never let me forget it.”

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Godden has worked at Albion Stone for 25 years. Albion quarries Portland’s stone, all of which is owned by The Crown Estate as part of its marine portfolio that encompasses the British coastline out to a nautical mile. With dulcet Dorset accent and dressed in weather-beaten highlighter-orange overalls, Godden next drives us round and down the sides of the quarry at Fancy Beach. At the very bottom are two dark tunnels – entrance and exit. With emergency breathing equipment slung over our shoulders and clutching a torch, we enter Portland’s first mine to, as he puts it, “take the cheese from the sandwich.”

The mine is organised in six metre cubes. It’s underground Jenga. A couple of miles of boxy voids, they line up to form tunnels, but have also variously been excavated above, below, right, left. You find yourself calculating 12-metre drops, or 54-metre long corridors. A huge yellow tube worms through from the entrance to the back of the mine, pumping in fresh air to counteract the forklift trucks that reverse laden with mammoth blocks of white stone.

At the very end of the warren, a shiny metal box headbutts the mine wall, slowly sawing in grooves with a diamond-tipped chainsaw – “with mass, force and tensile strength; there’s a black art to diamond tips!” Into the gaps, steel inflatable bags are placed then filled with high-pressure water, forcing and breaking the stone away from the rock face. When the bag bursts, there’s no bang, just water. A simple and clever technique pinched from the travertine mines outside Rome; it has eliminated the need for blasting.

Each piece, no more than sixteen tonnes, is marked up with blue spray paint detailing the exact location – for quality control and stock taking – and its volume in cubic metres.

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The mine is a necessary innovation for Portland. Working underneath the village cricket pitch, this mine is less noisy, dusty, and scarring than the traditional open-air quarries above. “We’ve had to learn a lot of new skills and quickly,” Goddon explains, confirming that the mines are proving more economic, more effective, and able to open up new sites across a limited resource. Impressively though, he has also roughly calculated that history has only so far removed 36% of all potential stone on the island. But here,
as with many places in Britain, natural resources sit cheek by jowl with
a 12,000-strong resident community.

Above ground, Richard Mort, who, with his team of stonemasons at Albion, shape and create the final product for all kinds of customer internationally, averaging 75–80 pallets of finely hewn stonework per week – “From Aunt Mary down the road to big London developments.”

As below, it’s a pragmatic mix of technological capability and human ingenuity. But all the high-techery has clear roots in solving those stone age problems: how to move stone and how to shape it. CNC machines help create the curving panels hugging St James’s Market’s distinctive rounded facade, but the finishes are all done by hand, cutting in the anodised aluminium detailing. “Our tools have changed little: our mallets are now nylon, our chisels metal, but little else.”

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“A lively stone, full of character,” each
St James’s Market piece is fixed in metal cases to become complete panels. This is done before going on site, where they are simply hoisted into the right place. “Bam bam – it’s just one big puzzle. Eases disruption. It’s the way it’s going in London.”

London is made of Portland. Since the first London Bridge made of stone, to the rebuilding after the Great Fire of London, our city has looked to Portland to provide a great source of practical, pure and beautiful stone.

Regent Street is an elegant canyon of it, Trafalgar Square a busy tourist cove of it, the cenotaph a lonely stack. It’s part of our city’s visual consciousness. But St James’s Market marks a new, deeper layer of appreciation, one that recognises the beauty of nature’s variation, and an application that shows us exactly what London’s made of. Independently, Goddon and Mort turn and agree – “You’ve picked the perfect stone for me.”