It includes the melting on the raw compound applying oxyhydrogen flame plus the crystallisation on the melted droplets to form a cylinder. Graded 9 about the Mohs-hardness scale (graded one-ten), the resulting sapphire crystals are pretty much scratch-evidence and really tricky, guaranteeing an unhindered vision at all times. I agree https://www.watchesworld.com/the-most-coveted-watches-in-the-uk/