It consists of the melting of the raw substance employing oxyhydrogen flame and the crystallisation of the melted droplets to type a cylinder. Graded nine to the Mohs-hardness scale (graded one-10), the ensuing sapphire crystals are practically scratch-evidence and very challenging, guaranteeing an unhindered eyesight all of the time. Most https://www.watchesworld.com/top-10-dive-watches/