Diamond Faceted Black Tungsten Carbide Band

What is Tungsten :  

Tungsten Carbide became a popular material due to its extreme hardness and high resistance to scratching. It is about 10 times harder than 18K gold, 5 times harder than steel and about 4 times as hard as titanium.

Tungsten Carbide measures between 8 and 9 on the mohs hardness scale compared to diamonds which measures 10. Rings made from Tungsten Carbide are known to hold their shape, due to their extreme hardness.