There's an art in chipping stone.

One wrong tap and the shape of a block can be changed completely or rendered unusable.

But that artistry is what attracted Josiah Gowans to the trade of stonemasonry.

"It's intricate. You have to take your time. There's stages that you have, so you have to start small," he said.

"The way it chips away, how you can curve and mould into something that comes from a square block, is just incredible."

Intricate stonework is still done by hand. ( ABC Radio Sydney: Amanda Hoh )

Mr Gowans, a former landscaper, is currently working on restoring the sandstone window frames of Woollahra Public School.

He is only a few months into his apprenticeship as a stonemason at the New South Wales Heritage Stoneworks in Alexandria, one of the last few stoneworks yard that restores and repairs Sydney's sandstone facades and monuments.

The stone arrives from the few quarries still in existence around NSW, before the massive blocks are cut down in the saw shop using programmable circular saws.

The more intricate work is done in the banker shop, where the rhythmic "clink clink" of mallets and high-pitched squeals of electric chisels sound from the hands of the eight to 10 masons.

Josiah Gowans studied stonemasonry through TAFE and has been an apprentice for a few months. ( ABC Radio Sydney: Amanda Hoh )

Working in a niche trade

Mr Gowans is only one of about 60 heritage stonemasons in the state, and there are very few learning the trade.

Manager Paul Thurloe said while there was a big industry in stone homewares, furnishings and cosmetic sandstone architecture, traditional heritage masonry was a "very niche market".

"When I first started I was told, 'Get out of it, there's no future here, machines will take over'," he said.

"But the increase in machinery has been a blessing. It allows us to concentrate on the technical aspect of the craft."

Mr Thurloe says he enjoys mentoring the next generation to "keep the craft alive". ( ABC Radio Sydney: Amanda Hoh )

Mr Thurloe has been a stonemason for 27 years.

His favourite workshop in the yard is the carving studio, which is filled with restored copies of stone monuments and head busts, including one of Charles Darwin.

While stonemasons don't spend as much time here as in the banker and saw warehouses, Mr Thurloe said it was where the craft was fully realised.

"It's like any artist's studio; it's a bit of a mess, with pieces we've invested a lot of time in," he said.

"It's immensely satisfying to create things with your hands and that will last longer than you will. It's a tangible, satisfying work."

Much of the heavy labour of cutting stone has been replaced by machine saws. ( ABC Radio Sydney: Amanda Hoh )

Restoring history

Mr Gowans said hardly any students were studying the trade at TAFE when he switched careers.

But Mr Thurloe doesn't think stonemasonry is at risk of being lost.

"Stonemasonry isn't dying but it's not growing either," he said.

It takes years to master the art and eye for stonecarving. ( ABC Radio Sydney: Amanda Hoh )

"Between the 1930s and '60s, there wasn't much value placed on our old buildings. But ever since the green bans, people have put value on these buildings.

"The golden era of stonemasonry, unfortunately, has past. There are new buildings, new technology, concrete, steel, glass.

"As long as we still value those old buildings, they still have a place."