It consists of the melting with the raw substance utilizing oxyhydrogen flame as well as crystallisation from the melted droplets to form a cylinder. Graded nine about the Mohs-hardness scale (graded 1-ten), the resulting sapphire crystals are just about scratch-evidence and really really hard, making certain an unhindered eyesight continually. https://www.watchesworld.com/the-most-coveted-watches-in-the-uk/