More than ever cleavages are the talking point around dining-room tables, and no dinner party these days, it seems, can afford to be without some old Princesses and Countesses.

A dinner party can only be judged by having the right sort of ladies present.

Slate is back. It has become desirable again but not outdoors to keep the weather out but indoors to keep diners, and interior designers happy and status enhanced, as well as slate house signs and garden decor; we are now demanding pre-Cambrian era tableware, using 770-million-year-old cheeseboards, runners made from ancient greenschist facies, and Orcadian chopping boards. No tablescape should be without a set of chic tableware made from terrigenous sediments and centuries-old mud.


Millions of years in the making, slate has many uses. In the Second World War, Wales’s Manod quarry was used to store art treasures from London’s National Gallery and the Tate.

The Slate Landscape of Northwest Wales has become the UK’s newest UNESCO World Heritage Site – the UK’s 33rd UNESCO World Heritage Site and the fourth in Wales, following the Pontcysyllte Aqueduct, Blaenavon Industrial Landscape, and the Castles and Town Walls of King Edward in Gwynedd. The designation recognizes that the area is an important Cultural Landscape.

Gwynedd became a world leader in the production and export of slate in the 1800s. Slate has been “won” in the area for over 1,800 years and used to build parts of the Roman fort in Segontium in Caernarfon and Edward I’s castle in Conwy. Cardiff’s Wales Millennium Center uses waste Welsh slate in many different colors- purple slate from Penrhyn, blue from Cwt-y-Bugail, green from Nantlle, grey from Llechwedd, and black from Corris.

By the 1890s, the Welsh slate industry produced almost 500,000 tonnes of slate a year, around a third of all roofing slate used in the world in the late 19th century. Westminster Hall in London’s Houses of Parliament, the Royal Exhibition Building, and Copenhagen City Hall are all made from the Welsh state. In 1830, half the buildings in New York had roofs made of Welsh slate.

Penrhyn and Dinorwig were once the two largest slate quarries in the world and Oakeley at Blaenau Ffestiniog was the largest slate mine in the world. Cilgwyn, the oldest quarry in Wales, closed in 1914, though it later reopened. Oakeley was mothballed in 2010.  Penrhyn still produces slate, and the Greaves Welsh Slate Company produces roofing slates and other slate products from Llechwedd.

The National Slate Museum is housed in the old Dinorwig Quarry near Llanberis.  Its exhibits include Victorian slate worker’s cottages and the world’s largest working water wheel. The old Llechwedd slate caverns have been converted into a visitor attraction. Its Deep Mine is accessed by Britain’s steepest passenger railway. The Llwyngwern quarry near Machynlleth is now the location of the Center for Alternative Technology.


The novels of quarryman’s daughter, Kate Roberts, immortalize the old Welsh-speaking slate communities and its “rock men”, “rubbish men” and “bargain gangs”. Modern companies also preserve traditions and handicrafts.

Founded in 2013 by explosives engineer Andy Carson, North Wales Slate, and Stone Ltd acquired the Llechwedd Slate Quarries in 2014n creating Northern Welsh Quarries Ltd as well as manufacturing slate coasters, table placemats, wine racks, kitchen worktops, plant pots, the company also deals in roofing, cladding, coping, paving, aggregates, lintels and quoins, and cornerstones.

Slate is also used to make billiard tables. In Letchworth, Hertfordshire the Slate Furniture Works make “virtually rain resistant” slate tables, some out of reclaimed snooker tables. Ben Thomas runs The Slate Workshop in Five Roads, near Llanelli in south Wales. The slate is sawn to size, then shaped and prepared using hand tools. The town’s Welsh Slate Boutique sells egg and teapot stands, condiments trays and tiered cake stands as well as memo boards made from Gwendraeth Valley slate.

Kevin Thomas’s Swansea “Valley Mill” makes photo frames, tealight candle holders, and cork-padded coasters out of 100% Welsh Slate in his Cryant workshop. There is even a Blue Slate Gin.

Pieces of hand-shaped, foliated, fissile (splittable), igneous metamorphic rock are much in demand. Ordovician has never gone out of fashion, and Cambrian is coming back into vogue in Scotland. Albeit Spanish, Donny Carstairs hopes to soon use Scottish slate.

With demand still high for “architectural” slate for flooring and cladding as well as slate chips for hard landscaping and large resources of workable slate still remaining, the viability of resuming mining in Scotland’s “Slate Belt” is being studied. Especially around the Glens of Foudland.


Credited with the concept of slate tableware, the Fife farmer’s son founded the now five-brand “Selbrae House”, having graduated as an accountant from Edinburgh University. The Kirkcaldy-based family company designs and produces homewares and gifts, using sustainable Scottish raw materials. The Just Slate Company homeware range has almost single-handedly turned slate into a trendy item and revived its fortunes.

Another brand, “Scottish Made” comprises etched wooden homes and tableware, produced from sustainable wood from the local “Dynamic Wood” social enterprise project. “Linen Table” offers linen napkins, mats, tea towels, and table runners, produced from linen which comes from the last traditional linen mill in Scotland.

Handcrafted in Scotland “Just Slate” homewares are foam-backed to protect surfaces and finished with a food-safe coating.

Says 45-year-old Donny who was born and brought up in the home of golf, St Andrews, in the East Neuk of Fife: “Mum began Scottish Everlastings, a home accessory company, in 1992 and the idea of creating a Scottish homeware and gift brand, created from natural products.”

In ancient times, large rock slabs were used as graves and hearthstones.  Later, the laminated rock was split into thinner sheets which were overlapped to form water-tight roofing.  Many well-known Scottish buildings – Armaddy Castle (1676), Stalker Castle in Appin (1631), Cawdor castle, Invernesshire,  Balmoral Castle, and Glasgow Cathedral – are all made from Scottish slate. It was produced in four different areas.  Ballachulish near Fort William, the Highland Boundary stretching from Arran in the west to Dunkeld in the east, and Macduff slate from near Huntly in Aberdeenshire in the slate hills of Foudland (Groome).

For three centuries, with Welsh slate, Scottish slate roofed the world. The industry was based on the west coast of Argyll, in the islands in the Sound of Lorn, south of Oban.

The Scottish slate industry probably started on the island of Easdale. There is a record of a cargo of slates being sent to St Andrew’s in 1168. The Earl of Breadalbane established the Marble and Slate Company in 1745. As the demand increased, the company opened quarries on the adjacent slate islands of  Ellanbeich, Luing, and Seil. Ellanbeich (“Isle of Birches”) is no longer an island but connected to Seil by slate waste.

The islands formed part of the huge Breadalbane family estate which were cousins of the Dukes of Argyll. The title, Marquis of Breadalbane, brought with it the ownership of Nova Scotia. Many buildings in the east Canadian seaboard have Easdale roofs. Easdale slate is gunmetal grey. Foudland, whose faces at one time produced over one million hands split slates a year, midnight blue with a crystalline sheen. Ballachulish slate from the East Laroch and Khartoum quarries was grey-black with a slight sheen with pyrite grains concentrated in quartz veins. Macduff or Birham is generally blue-grey in color, often with a purple hue. Production started to decline after 1900 with slate being replaced by mass-produced clay tiles. The largest quarry at Ballachulish closed in 1955 and the last one in the ‘60s.

The traditional slate industry is something the Carstairs family wants to commemorate. And that’s when cleavages come to the front, and why it is so important to have more ladies seen around a dinner table.

Cleavage means the ability to split apart. Slate’s poorly defined cleavages meant that when split, the rock had to be cut into prescribed sizes. A skilled “napper” or cutter produced various sizes of slate – Princess (600x350mm), *Duchess” (600x300mm), *Countess” (500x250mm) and “Ladies” (400x200mm). Welsh quarrymen used the same terms.

Slate rock was removed from the foreshore by inserting hardwood wedges in cracks at low tide. As the tide rose, the wedges swelled, and cracks widened and split into manageable blocks after a number of tides. The block was hauled above the high-water mark for riving (splitting), napping, and trimming into roofing slates. When seawater could no longer be used to break out the slate, gunpowder was introduced.

At the peak of the slate mining industry, Easdale had a community of more than 500 working or “winning “seven quarries. Women and children with creels on their backs carried the made slates to the harbor for stacking.  Before railway lines and small locomotives housed in the “coal-free” made haulage easier, horses were used. Clydesdales worked on Easedale until its quarries closed down in 1911.

Before the days of diamond wire saws, hydraulics, compressed air drilling, and lasers, the splitters – often sitting in water- worked in sheltered pits or “scathies” and were paid by the thousand slates sold. The count was tallied up on a piece of slate. Thus, the term “Put it on the slate.”

Easdale island is now a Conservation Area and many houses are listed buildings. Repairs and extensions must be in slate. To do this, slate has been recovered from dismantled buildings in Glasgow and elsewhere. Slate’s durability continues and British slate continues to be used across the world in various time-worn forms. And more and more people are realizing that poor cleavages aren’t that bad at all.