There are four main economic evaluation conditions for emeralds, cụ thể là: ①Color: emerald green and dark green are better, greenish blue and yellowish ones are inferior; ②Transparency: tinh thể rõ ràng, clear and bright is the best, translucent Those who can only be included in the third grade; ③Purity: emeralds are often flawed, pure ones are rare and [...]
