Vacuum / Ion Plating:
Rutile is a mineral composed primarily of titanium dioxide. Rutile has among the highest refractive indices at visible wavelengths of any known crystal, and also exhibits a particularly large birefringence and high dispersion. Small rutile needles present in gems are responsible for an optical phenomenon known as asterism. Asteriated gems are known as "star" gems. Star sapphires, star rubies, and other "star" gems are highly sought after and are generally more valuable than their normal counterparts.
Vacuum/Ion Plating is more durable and wear-resistant than traditional plating methods. Additionally, its great advantage is environmental consciousness as it avoids chemical solution during the process and it’s irritation-free for the skin. Vacuum/Ion Plating is an advanced technique normally in the watch, electronic and space industries. The object is placed in a vacuum chamber, which is pumped down to the desired vacuum pressure. The chamber is then heated to the target temperature to evaporate the material, which is sprayed onto the object, producing a thin layer of coating.