Lapis Lazuli and Turquoise, the birthstones for December

Colours
Turquoise is a light blue opaque stone with hues from sky blue to a grey green. In many cases turquoise has veins or blotches running through it. These veins can be black brown or light grey in colour and is dependant upon their origin.
Lapis Lazuli is a dark blue colour, which can have flecks of pyrites as inclusions that sparkle in the light. Its marble like finish and beautiful deep blue finish make it a very desirable stone.

Physical properties
Turquoise has a Mohs rating of 6 meaning it is not one of the hardest stones. Many times turquoises will be treated with wax in order to make them harder.
Like the Turquoise, Lapis Lazuli is a moderately hard stone (between 5 & 6 on the Mohs scale) that is often treated with wax. It is advised that lapis is kept away from acidic substances and it should also be kept out of sustained direct sunlight.