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)
The diamond typically has a diamond shape, a parallelogram with four equal sides, placed on one of its points. The sides are sometimes slightly rounded and the four vertices placed in a square, making the sign look like an astroid.