In this issue, NASA introduces you to the basic knowledge about diamonds and precious stones. Indeed, as a fanatic of jewelry and diamonds, do you know where the world's largest diamond processing center is and where the world's largest gem processing center is? Where is the largest diamond processing center in the world: (1) Small diamond processing center-Mumbai, India; (2) A large diamond processing center-new york, USA; (3) Antwerp, Belgium, an exquisite diamond processing city; (4) Fine small diamond processing center-Tel Aviv, Israel. Where is the next largest gem processing center: (1) World Gem City-Burstein, Germany (2) Jade Roughing City-Jaber, India; (3) Sapphire City-Bangkok, Thailand; (4) Emerald and "Four Emperors and One Empress" processing center-Hong Kong; (5) The middle and low grade gem processing city-Jiafu, Japan.