A basic variety of aluminium oride,brown colour,high hardness and great toughness.
A basic variety of aluminium oride,brown colour,high hardness and great toughness.
刚玉的基本品种，棕褐色，硬度高、韧性大。
A basic variety of aluminium oride,brown colour,high hardness and great toughness.
刚玉的基本品种，棕褐色，硬度高、韧性大。