Lithium Niobate

In the gemstone world, lithium niobate is perceived as a diamond simulant + the colors range from yellow, blue, red, green, violet and colorless + the stones are grown using the Czochralski process + due to its unique electro-optical, photoelastic, piezoelectric and non-linear properties, it's used extensively in the telecoms market, e.g. in mobile telephones and optical modulators.