Ruby is one of hardest known material with consistent quality available on a commercially economical scale. With a hardness of 2300 HV it is much more harder then most of the known hard materials like ceramics, etc. Ruby raw material is grown in a factory by Melting ultra pure Al2O3 at temperature higher then 2000 deg. Celcius to create a single crystal. This hard material has the ability to be polished to a very good surface finish. Applications which need wear resistance to metals and chemicals use ruby balls for longer life. In terms of visual appearance, Ruby Ball can have a surface finish of No Scratch/Dig at 20x Magnification level (depending on the diameter of the Ruby ball lens).