It requires the melting in the raw material utilizing oxyhydrogen flame along with the crystallisation with the melted droplets to form a cylinder. Graded nine about the Mohs-hardness scale (graded 1-ten), the resulting sapphire crystals are practically scratch-proof and really really hard, ensuring an unhindered eyesight constantly. We take the https://www.watchesworld.com/top-10-dive-watches/