A certified diamond is a diamond that has been graded and verified from a reputable grader independent of the jeweler from which you are purchasing it. The two most respected authorities on gemstone quality are the Gemological Institute of America (GIA) and the Gem Certification and Assurance Lab (GCAL). These institutions exist to protect consumers against fraud and to objectively determine gemstone quality.
What to Look for When Purchasing a Diamond
Diamonds are graded on four distinct characteristics commonly referred to as the 4 c’s: color, clarity, cut, and carat.
Color: Excluding fancy-color diamonds, the diamond is graded on a colorlessness, that is how close it comes to being completely free of color. Most diamonds have some hint of yellow or brown which lowers its value.
Cut: The cut gives the diamond its brilliance and fire. Facets are cuts that take advantage of reflecting light. The cut is ranked as very good, good, medium, or poor.
Clarity: The clarity is measured under a 10x magnification and is determined by blemishes and inclusions. The range is flawless to imperfect with flawless being the most expensive but also a rarity.
Carat: The carat is the actual weight of the diamond. A one-carat diamond weight 1/5 of a gram.
“What Is GIA?.” Gemological Institute Of America. N.p., n.d. Web. 25 Oct. 2011. <http://www.gia.edu/about-gia/index.html>.
“Diamonds.” College of Natural Resources – UC Berkeley. N.p., n.d. Web. 25 Oct. 2011. <http://nature.berkeley.edu/classes/eps2//wisc/Lect6.html>