As far as gems are concerned, beauty is the first condition that gems must have. The beauty here is composed of many factors such as color, tính minh bạch, sự thuần khiết, ánh sáng, vân vân. When these factors are combined well, đá quý có thể rực rỡ và đẹp. đầu tiên, colors are divided into two series: colorless and colored. Giữa [...]
