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.
Diamond willow
There are at least six different species that have been identified as being susceptible to diamonding, including "Salix bebbiana", the most common diamond willow, plus "S. pseudomonticola", "S. arbusculoides", "S. discolor", "S. scouleriana", and "S. alaxensis".