Humans have been searching, mining and using gemstones for nearly 6000 năm. Ví dụ, the famous Chinese “ngọc Hetian” has been discovered as early as the primitive society. Theo số liệu thống kê chưa đầy đủ, there are more than 600 kinds of gem mines discovered and mined in the world, and these gem resources are mainly distributed in […]
