Diamond type
Diamond type is a method of scientifically classifying diamonds by the level and type of their chemical impurities. Diamonds are separated into four types: Type Ia, Type Ib, Type IIa, and Type IIb. The impurities measured are at the atomic level within the crystal lattice of carbon atoms and so, unlike inclusions, require an infrared spectrometer to detect.
Diamonds (suit)
Normally diamonds are red in colour. They can however be depicted in blue, which is the case for example in bridge (where it is one of the two minor suits along with Clubs).