The rich gem resources in the world are mainly concentrated in Africa, เอเชีย, America and Oceania. 1. Africa The African continent is rich in gem resources and is known as the “World Gem Warehouse”. It is rich in diamonds, ทับทิม, ไพลิน, golden emeralds, มรกต, สมเด็จ, อเมทิสต์, peridot and turquoise, among which diamonds are the most […]
