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.
Pink diamond
The same four basic parameters that govern the grading of all gemstones are used to grade pink diamonds–the four Cs of connoisseurship: "color", "clarity," "cut" and "carat weight". Color is considered the absolute most important criterion in grading a pink diamond and determining its value. However, size is an important consideration in a pink diamond's value. The larger a pink diamond, and the better its color, the more valuable it will be.
One of the most famous pink diamonds is the Pink Star — at 59.60-carats, this type IIa diamond is the largest vivid pink diamond in the world. In 2014, auction buyer was unable to pay the promised sum and was subsequently forced to default on its purchase. Among famous pink diamonds; the Daria-i-Noor is the largest pink diamond in the world, measured at 182 carats; together with the Noor-ul-Ain, it is the oldest known pink diamond, both belonging to the Iranian crown jewels.