It consists of the melting on the raw substance using oxyhydrogen flame and also the crystallisation of the melted droplets to sort a cylinder. Graded 9 to the Mohs-hardness scale (graded one-10), the ensuing sapphire crystals are almost scratch-proof and really hard, guaranteeing an unhindered vision constantly. In case repairs https://www.watchesworld.com/the-most-coveted-watches-in-the-uk/