“Her stone stays whole.” Why a 76-year-old Cornish stone cutter is selling his last 186 butterflies at a special price

His hands can no longer hold the saw. A Birmingham wholesaler offered to buy every slab he has left by the kilo. Kenver Trethewey turned him down and chose something else.

St Just, Cornwall. On the shelves behind Kenver Trethewey’s little rock shop sit flat boxes of small stone butterflies: purple amethyst, blush-pink rose opal, deep blue sodalite, golden tiger’s eye. Each pair of wings was cut by hand from a single slab of stone, so the pattern runs from one wing straight into the other.

There are one hundred and eighty-six of them, and there will never be more. At seventy-six, Kenver’s hands can no longer hold the saw.

This spring a wholesaler from Birmingham wanted the lot, every finished butterfly and every uncut slab, by the kilo. The plan: slice the stone paper-thin, back it with resin, dye the dull pieces bright and sell them as “crystal butterflies” in gift shops for up to £120.

Kenver said no.

Instead he is selling the butterflies exactly as they came off his bench, straight to the people who will set them in a window. For £49.

The boy who found a Cornish diamond

The cliffs around St Just are riddled with old tin and copper mines, and the spoil heaps they left behind still turn up quartz crystals so clear that people here have always called them Cornish diamonds. Kenver grew up here, the son of a tin miner.

“I was fourteen, poking about on the old mine tips above my grandad’s cottage with my cousin, and saw a glassy tip sticking out of the rubble,” he says. “I dug it out with Mum’s garden trowel, and my cousin took a picture with his little Brownie camera. I’ve still got it. Clear as window glass, six sides, a point on the end. Nobody made that. The ground did. I never got over it.”

He learned to cut and polish what he and other collectors found along that coast. In 1982 he opened a small rock shop on the main road through St Just, with a cutting room in the old granite outbuilding at the back. He has been at the saw ever since.

Loveday, and what a butterfly means

His wife, Loveday, taught at the village primary school for twenty-eight years. She was no collector, until the day he held a slice of amethyst up to the kitchen window and the light came through the purple.

From then on, every June, they drove the old Volvo estate across the Channel to the great mineral show at Sainte-Marie-aux-Mines in Alsace. She picked the slabs. He cut them. And she kept a stone book: where every piece came from, and what each stone has stood for over the centuries.

She loved the real thing, too. Every summer the red admirals and painted ladies came in off the sea and settled on the buddleia she grew along the garden wall. Her granny had taught her an old saying: a butterfly at your window means good news is on its way.

After that she wanted a butterfly from every good stone that came through the shop. Together they set aside the best slabs of eight stones for butterflies and nothing else. Kenver sold a few to regulars and to galleries in St Ives, where they went for £65 apiece.

When the house went quiet

In the late autumn of 2023, after forty-nine years of marriage, Loveday passed away. For almost a year Kenver did not unlock the workshop.

One sleepless October morning, with the wind coming in off the Atlantic, he finally went out to the bench. Her stone book still lay there, open at the page where she had listed the slabs saved for butterflies.

“She’d planned every one of them,” he says. “The least I could do was cut them. And she always said a butterfly means starting over. I thought if anybody needed one, it was me.”

For seventeen months he cut almost every morning. Three hundred and seventy-two wings. One hundred and eighty-six butterflies, each one different, because no two slabs of stone ever grew the same way.

One slab, one pair, and a test you can do at home

Every butterfly starts as one slice of natural stone. Kenver traced both wings side by side, cut them out together, carved the veins by hand and polished them until the pattern came alive. Once a slab is cut, that pattern exists nowhere else.

Loveday always told customers what each stone stood for, “not as a promise, just as a reminder”: amethyst for a calm, clear head, rose opal for a soft heart, sodalite for honest words, tiger’s eye for courage, agate for new beginnings, red gum flower for warmth, apatite for the push to start something and yellow calcite for a lighter heart.

Telling real stone from a copy is easy. Real stone is cold to the touch and heavier than it looks; resin feels warm and light. Then hold it to a window. On amethyst, red gum flower and yellow calcite, the light glows through the edges of the wings.

“Look at the cut edge,” says Dr Hilary Penrose, a retired mineralogy lecturer from Camborne. “In real stone the pattern runs all the way through. A printed or dyed copy stops at the surface.”

“Not one more slab”

This spring the X-rays came back from the Royal Cornwall Hospital in Truro. Arthritis has worn through the joints at the base of both thumbs, and a tremor in his right hand has been getting worse for three years. His grip is barely a third of what it once was.

It is not only his hands. By ten in the morning he is worn out, and by noon he can hardly lift a slab onto the bench.

“A hand that shakes and a diamond blade don’t belong in the same room,” the consultant told him. “Not one more slab.”

The offer from Birmingham

Word of the Trethewey stock had reached a crystal and home-décor wholesaler near Birmingham through dealers at the mineral shows. A week later the buyer stood outside Kenver’s shop on the main road. Seven pounds a kilo, cash. For rough stone, a fair price.

Then Kenver asked what would happen to it. Sliced as thin as it would go, glued to resin, the dull pieces dyed bright, cut into butterflies by machine.

That evening his son Jago, who fishes out of Newlyn, had a better idea: sell the butterflies Kenver had already cut, straight from his bench, with no wholesaler and no gift shop taking a cut.

£49 for a butterfly that exists only once

Each butterfly is about 10 to 13 centimetres wide and stands on a slim silver steel stand shaped like a butterfly’s body, packed in a padded box. Choose from eight stones: amethyst, rose opal, sodalite, tiger’s eye, agate, red gum flower, apatite and yellow calcite.

The price is £49: less than a resin copy in a gift shop, and below the £65 the galleries charged. It covers the stand, the box and the postage, with no markup on top.

“I want these in the windows of people who are starting something,” Kenver says. “A new home, a new job, a first year without somebody. That’s what Loveday would have wanted.”

What buyers say

Word spread among rock collectors first. Then it reached people who had never owned a stone in their lives.

The present that says “begin again”

Mothers buy them for daughters moving out. Friends buy them for friends after a divorce. Grandparents buy them for graduations. Widows buy them for themselves. A butterfly says something without a card, and a stone one never fades.

The last 186

Those boxes hold everything that is left from forty-odd years of slabs Loveday picked. Kenver’s hands and his strength are done, and there is nobody else at the saw. When the last butterfly is packed, it is over.

Jago packs every order by hand, and every butterfly comes with a 90-day money-back guarantee. “Hold it to the window,” Kenver says. “If it doesn’t make you smile, send it back.”