Plum Slate Riven Almost brown but with definite purple hues plum slate is visually very appealing.  Sometimes hints of green show through adding interest and depth to this beautiful slate. Again, a lovely uniform tone but coupled with the unique purplish colour. Sizes Available (LxWxD) : 1 cm thick at £ 19.20 / m² + vat 1 cm thick at £ 21.30 / m² + vat 1 cm thick at £ 28.00 / m² + vat 0.8cm thick (Wall Tile) at £ 26.40 / m² + vat