Yttrium oxide stabilized zirconia is a high-performance structural ceramic that can be used to make various special purpose knives and scissors; It can be used to produce automotive engines due to its high thermal conductivity, low coefficient of expansion, good thermal stability, and high horsepower and fuel efficiency at 1650 ℃ without reducing working intensity. Artificial gemstones processed with yttria and zirconia have many characteristics that natural gemstones do not possess.