Why We Grind Both Sides: The Truth About Honed Slate

Why We Calibrate Both Sides of Our Honed Slate

In the trade, "Standard" and "Premium" grades typically refer to the appearance of a slab on its surface. For our honed slate, those labels don't apply. We don't just "pick" a good-looking stone; we engineer a superior one through a strict two-stage process.

Stage 1: Precision Calibration (Front and Back)

Before we even think about the finish, we make the slab "true." Most suppliers only calibrate the underside. We machine both the front and the back to ensure every single slab is perfectly flat and consistent in thickness.

Stage 2: The Mirror Hone

Once the slab is perfectly flat, we move to the honing stage. We grind the face down to a mirror-smooth finish. Because this process cuts deep into the slate to remove the natural riven surface, the stone’s true colour and character are only revealed at the very end.

The Result: High-End Consistency

After this process, the slab has been transformed from a raw slab into a precision-machined product. You aren't gambling on a "grade"—you’re getting a high-end, consistent finish that is ready to lay straight out of the crate.

The Reality of Honing Brazilian Slate: Why "Clouding" Happens

When you take a natural cleft Brazilian slate and hone it flat, you’re essentially "peeling back the skin" of the stone. Here’s why that often results in cloudy or patchy patterns:

1. It’s Not One Solid Color Inside

Unlike a ceramic tile that’s the same all the way through, Brazilian slate is made of thousands of microscopic layers of compressed mud and mineral.

• The Issue: When you grind it flat, you aren't staying on one layer. You are cutting across multiple layers at once.

• The Result: The "clouds" are just different mineral layers being exposed. It’s like sanding a piece of plywood—once you go through the top veneer, you see the different grain underneath.

2. "Hard Spots" vs. "Soft Spots"

Brazilian slate has a high quartz content. Quartz is much harder than the rest of the stone.

• The Issue: Your diamond pads will cut the softer parts of the stone faster than the hard quartz patches.

• The Result: This creates a difference in how light hits the surface. The soft areas look dark and matte, while the hard quartz areas look lighter and "cloudy."