Behind the Quarry — How Natural Stone Goes from Rock Face to Slab

The Quarry: Where It Begins

Marble and granite quarrying is fundamentally the extraction of blocks from a mountain. At a marble quarry like those in Carrara — where quarrying has continued for 2,000+ years — the active quarry face is blasted, wire-sawed, or cut with diamond wire into manageable blocks. A typical commercial block weighs 15–25 tonnes.

Gang Saws and Wire Saws: Turning Blocks Into Slabs

Most marble blocks are processed by multi-blade gang saws — large frames holding dozens of steel blades that oscillate through the block simultaneously, cutting up to 60 slabs in a single multi-day pass. The result is a slab bundle that remains in original sequence from the block, critically important for bookmatching.

Calibration, Polishing, and Finishing

Raw-sawn slabs have a rough, uneven surface. They go through calibration (machine-grinding to a consistent thickness) followed by polishing — multiple passes through increasingly fine abrasive heads. A standard polished finish typically requires 7–12 polishing heads.

Fill, Repair, and Quality Grading

After polishing, slabs go through quality grading. Natural defects — open veins, pitting, cracks — are evaluated. Premium grades export as-is; commercial grades are filled with epoxy or polyester and sold at lower prices.

Container Loading

Slabs are loaded into A-frame wooden crates, typically holding 6–10 slabs per crate, and loaded into 20ft or 40ft containers. Ask your supplier for container loading photos before the vessel departs.