Generally, Diamond and CBN are called “Super Abrasives” or “Superhard Materials”.
Obviously the wheels manufactured with these abravises are called Diamond or CBN grinding Wheels.

DIAMOND
In general, diamond is used to  grind non-ferrous materials, because it reacts with iron.
• Cemented carbide
(Tungsten Carbide)
• Glass
• Ceramics
• Fiberglass
• Plastics
• Stone
• Abrasives
• Electronic components and materials
 

CBN
 
CBN is used to grind ferrous materials.
• High-speed tool steels
• Die steels
• Hardened carbon steels
• Alloy steels
• Aerospace alloys
• Hardened stainless steel
• Abrasion-resistant ferrous materials