Sapphire is a precious gem belonging to the Corundum family, and it can be green, purple, yellow, blue, pink, etc. This stone is valuable, as are Sapphire stones, which are almost blue and have vivid colors. Very high. 

Like Ruby, Sapphire's hardness is calculated based on the Mohs scale and reaches 9 points. Therefore, it belongs to the precious gem group and is suitable for most types of jewelry with unique designs. Several Sapphire quarries exist in Yen Bai, Nghe An, Dak Lak, and Lam Dong.