Bluestone and basalt are both types of natural stone that are commonly used as pavers in Melbourne, Australia. Both bluestone and basalt are a type of volcanic rock that is black or dark grey in colour which will have catspaw surface holing to a percentage of each tiles surface. The percentage of catspaw is usually dependent upon the country of origin. Australian and European bluestone both have around 10% – 25% of any tiles surface containing catspaw whilst Chinese and Indian bluestone tend to have less catspaw, around 5% – 10% of any tiles surface.