Digging deep: Castlemaine slate

Close up of slate

Andrew Stephens

Posted April 10, 2018

Castlemaine slate lends its golden glow to many Victorian buildings. Meet the men who quarry it.

Most weeks, Peter Fleming hauls three cubic metres of Castlemaine slate out of the deep quarry where he has worked for 34 years. Sometimes, he strategically drills holes into the ground, deposits explosives, sets the fuse, and retreats to safety.

The explosion is more thump than thunder, but the gorgeous rock extracted is a pleasure to behold. “And it always looks better away from the quarry, when it is laid and cleaned,” Peter says.

Castlemaine slate, boasting golden earthy hues, is much sought by architects and landscapers, especially those keen on using local products with enormous character. Three cubic metres weekly, though, was not enough for the new RACV Cape Schanck Resort: builders needed about 20 cubic metres a week for the drystone walls and paving, so production was ramped up, bringing in 900 cubic metres over 14 months.

The quarry outside Castlemaine where Peter works has been going since 1953, starting as the Maltby family business but changing hands to Yarrabee & Castlemaine in 2005. It is the only site where Castlemaine slate can be sourced. Local quarries such as Mount Granite at Harcourt or the Pyrenees Quarry specialise in other stone.

Castlemaine slate is special, coming from a 35-kilometre-long seam. Geologist Clive Willman says this was created when the molten precursor to the adjacent solid granite pushed its way up from the lower crust. At many hundreds of degrees, it baked everything for a radius of 1.3 kilometres, particularly the mudstone and sandstone that form the bedrock around Castlemaine, turning the mudrock to the special, hard slate.

Yarrabee & Castlemaine’s sales manager, John Hardy, is a huge fan of Castlemaine slate: for many years he has attended world stone fairs and has never seen anything to match the stone, which his workers split into laminates using hammer and chisel, or work into manageable blocks for handmade walls.

While the extraction and splitting is a slow process, Hardy’s workers at the Taradale splitting yard and the Castlemaine quarry are not afraid of hard work, and some have learnt specialist stonemasonry skills, a craft vastly more common in centuries past. This is evident in Castlemaine where the slate is abundant in walls and patios, but also in recent buildings including the Castlemaine police station.

Some can’t get enough of it, though: with Peter Fleming’s years of hard yakka, you’d think he’d need a rest at weekends. Actually, he’s to be found doing private jobs – using Castlemaine slate.