It entails the melting in the raw substance applying oxyhydrogen flame as well as the crystallisation with the melted droplets to type a cylinder. Graded 9 on the Mohs-hardness scale (graded one-ten), the resulting sapphire crystals are just about scratch-evidence and very difficult, making sure an unhindered eyesight always. Linkedin https://www.watchesworld.com/the-most-coveted-watches-in-the-uk/