Abstract: Yttria-stabilized zirconia (YSZ) crystals are the most common synthetic gemstone with advantages of high refractivity, strong dispersion, high hardness, and stable physical and chemical properties. Due to their ultrahigh melting point of 2 715 ºC, YSZ crystals were grown by the skull melting method without crucible. The yield of a single furnace is the primary indicator of its technological advancement and a major pathway for reducing production costs. To enhance productivity, the skull melting furnace with high power of 160 kW and larger diameter of 1.5 m was developed and mass production of 5 t YSZ crystals was realized, which is the largest yield of YSZ crystals in a single batch.