It consists of the melting from the Uncooked material using oxyhydrogen flame and the crystallisation on the melted droplets to sort a cylinder. Graded nine over the Mohs-hardness scale (graded 1-10), the ensuing sapphire crystals are just about scratch-proof and really difficult, making sure an unhindered eyesight at all times. https://www.watchesworld.com/the-most-coveted-watches-in-the-uk/