It includes the melting with the raw substance using oxyhydrogen flame and also the crystallisation with the melted droplets to variety a cylinder. Graded nine around the Mohs-hardness scale (graded one-10), the resulting sapphire crystals are nearly scratch-proof and really tricky, guaranteeing an unhindered eyesight at all times. In our https://www.watchesworld.com/top-10-dive-watches/