1. colour The colors of gems have differences in color hue, ความอิ่มตัว, and color brightness, as well as differences in the uniformity of color distribution and the degree of multicolor. The pros and cons of ruby color hue are: สีแดงบริสุทธิ์, สีส้มแดง, dark red, สีชมพู (สีม่วง) สีแดง, with pure spectral red as the top [...]
