A crucible (坩埚) and a saggar (匣钵) are containers used for chemical reactions or melting metals at high temperatures. Typically made from refractory materials such as ceramics or graphite, they possess properties of high temperature resistance and chemical stability. Crucibles are usually round with a wide base and a narrow top, aiding in uniform heating and control of molten materials. Crucibles and saggars are commonly employed in laboratories, industrial production, and metal smelting for high-temperature treatments and chemical reactions.