It consists of the melting with the raw compound working with oxyhydrogen flame and also the crystallisation with the melted droplets to form a cylinder. Graded nine around the Mohs-hardness scale (graded 1-ten), the ensuing sapphire crystals are nearly scratch-evidence and very hard, guaranteeing an unhindered eyesight at all times. https://www.watchesworld.com/the-most-coveted-watches-in-the-uk/