Mossanite 

As an alternative to diamond, Mossanite has many advantages, such as its availability without mining, optical properties far superior to diamond, low price, conductive properties similar to diamond, and Mossanite hardness of 9.25-9.5, second only to diamond 10, etc. Mossanite is widely used in jewelry in many developed countries and has been accepted as an environmentally friendly lab-grown gem.