It entails the melting of the raw compound using oxyhydrogen flame and also the crystallisation in the melted droplets to variety a cylinder. Graded 9 on the Mohs-hardness scale (graded 1-10), the ensuing sapphire crystals are virtually scratch-evidence and very really hard, making certain an unhindered vision continually. We wish https://www.watchesworld.com/top-10-dive-watches/