9ct yellow gold emerald diamond band ring

Gold : Because of the softness of pure gold, it is alloyed with silver, copper or palladium. The proportion of these other metals give yellow, white gold. Without precision, the gold used in jewelry is 18 K, corresponding to 75% pure gold.
Clarity : In order to establish the clarity of a diamond, the grader is using a 10x magnification. Diamond clarity scale ranges from FL (Flowless, no inclusion at all), IF (Internally Flawless, no internal inclusion), VVS1-VVS2 (Very Very Small inclusions), VS1-VS2 (Very Small inclusions), SI1-SI2-SI3 (Small Inclusions) and eventually I1-I2-I3 (Imperfect, for a diamond with inclusions visible even with the naked eye).
Diamond : In mineralogy, diamond is an extremely rare, precious and hard (named after the ancient Greek "unbreakable") metastable allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice.