This is a system that used to smelt one item to another.
Four same kind of metallurgical stones in the same level can smelt into a higher level stone through the metallurgical formula, four different kinds of metallurgical stones can smelt into a same level energy stone. The higher the stones’ level are, the less chance of the success you will have.
Four same kind of ring/bracelet in the same level can smelt into a higher level ring/bracelet when add a corresponding formula. The success rate of smelting ring/bracelet is 100%. The basic attribute of the metallurgical ring/bracelet is 140% of the former.
Four same kind of Pearls in the same level can smelt into a random pearl, with this random pearl you can get one other kind of pearl in the same level and same type.