Sapphire and ruby are the same mineral, corundum; the trade calls it ruby when chromium makes it red and sapphire for everything else, with iron and titanium giving the classic blue. At 9 on the Mohs scale it is the hardest stone we stock and shrugs off daily wear. Heat treatment is near-universal in cut sapphire, while the raw crystals here are untreated and opaque. Sapphire has been found in Scotland too, in small numbers. Hand-picked in St Andrews and posted UK-wide.