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.
Extraterrestrial diamonds
It has been proposed that diamonds exist in carbon-rich stars, particularly white dwarfs; and carbonado, a polycrystalline mix of diamond, graphite and amorphous carbon and the toughest natural form of carbon, could come from supernovae and white dwarfs. The largest white dwarf found in the universe so far, BPM 37093, located away in the constellation Centaurus and having a diameter of , may have a diamond core.