It requires the melting in the raw compound utilizing oxyhydrogen flame plus the crystallisation from the melted droplets to sort a cylinder. Graded 9 over the Mohs-hardness scale (graded one-10), the ensuing sapphire crystals are pretty much scratch-proof and really tough, making sure an unhindered eyesight all the time. Linkedin https://www.watchesworld.com/the-most-coveted-watches-in-the-uk/