It consists of the melting on the Uncooked material working with oxyhydrogen flame plus the crystallisation with the melted droplets to sort a cylinder. Graded 9 within the Mohs-hardness scale (graded 1-ten), the resulting sapphire crystals are nearly scratch-proof and really tough, making sure an unhindered eyesight all the time. https://www.watchesworld.com/the-most-coveted-watches-in-the-uk/