It includes the melting from the raw compound using oxyhydrogen flame and the crystallisation of the melted droplets to sort a cylinder. Graded 9 around the Mohs-hardness scale (graded one-10), the resulting sapphire crystals are pretty much scratch-evidence and really difficult, making sure an unhindered eyesight all the time. The https://www.watchesworld.com/the-most-coveted-watches-in-the-uk/