From 375 to 420, you can use sapphire boxing skills. For example, from 375 to 390, you can use shadow crystals to focus light, and you probably need 1 set of shadow crystals. From 30g to 420, you can use sparkling Qiu Shi or Eternal Forest Emerald or other drawings, and you need about 30 blue rough stones. After 30G.390, you can directly punch in 30 colorful gems, and you can buy colorful ones. So as to recover the cost. Regardless of the recycling cost, it will cost about 1000 to1500g, and if the cut stone can be sold, it will be subtracted. Finally, if you are an FM teacher, you can improve it by making rings and necklaces. Through decomposition, you can recover more costs and even make money.