Diamond Grading: The 4 C's
The 4 C's, when referring to diamond value, are color, clarity, carat weight and cut. All four factors are equally important in determining the final cost of a diamond. The criteria for diamond grading, most respected internationally, was developed by the Gemological Institute of America (the G.I.A.). The terminology and systems described on this page, are those of the G.I.A.
Following, is an explanation of these terms.
Clarity
Practically all diamonds contain naturally occurring internal characteristics called inclusions. The size, nature, location and amount of inclusions determine a stone's clarity grade and affect its cost. Clarity is determined using 10X magnification. By definition, if something is not visible at 10X, it does not effect the clarity.
FlawlessVVS1VVS2VS1VS2SI1SI2I1I2I3
1.Flawless/Internally Flawless= No inclusions visible, by an expert at 10X magnification
2.VVS1-VVS2= Very, Very slight inclusions very difficult for an expert to find under 10X
3.VS1-VS2= Very slight inclusions difficult for an expert to find under 10X
4.SI1-SI2= Noticeable, relatively easy to find under 10X. Not visible w/o magnification in a face-up direction.I1-I3= Obvious under 10X, may be visible to the unaided eye, I3's inclusions may effect the stone's durability.
Credit: http://gemologyonline.com/diamondgrading.html
ไม่มีความคิดเห็น:
แสดงความคิดเห็น