Grading Diamonds and Gemstones
Topazery grades diamonds and gemstones according to the guidelines of the Gemmological Institute of America (GIA). Read more by clicking on a topic below.
Grading Diamond Color
The Gemological Institute of America (GIA) developed a diamond color grading system in the 1950's. This color grading system is often called the D-to-Z scale and is the mosed widely used diamond color grading system in the world. Topazery's diamonds are graded according to this system.
Colorless diamonds are rare and beautiful stones. Near Colorless diamonds are lovely as well and are popular choices for diamond engagement rings. Faint color, Light color and Very Light color diamonds have a romantic glow like the varying colors of soft candle light. These diamonds are equally beautiful and unique.
Diamond color is a very personal choice!
|D E F||Colorless|
|G H I J||Near colorless|
|K L M||Faint color|
|N O P Q R||Very Light color|
|S T U V W X Y Z||Light color|
Diamond Clarity Grades
Clarity grades are used by diamond professionals everywhere. Clarity grades are also helpful to consumers who are making diamond buying decisions. The Gemological Institute of America's (GIA's) clarity grading system is the most widely used and respected in the world. Topazery's diamonds are clarity graded based on the GIA system. Clarity characteristics make every diamond unique; they are the diamond's fingerprint!
|Flawless||A Flawless diamond shows no inclusions or blemishes under 10x magnification.|
|An Internally Flawless (IF) diamond shows no inclusions when examined by an experienced grader using 10x magnification.|
|Very Very Slightly Included
(VVS1 and VVS2)
|Very, Very Slightly Included (VVS) diamonds contain minute inclusions that are difficult even for experienced graders to see under 10x magnification.|
|Very Slightly Included
(VS1 and VS2)
|Very Slightly Included (VS) diamonds contain small or minor inclusions which an experienced grader may observe with effort under 10x magnification.|
(SI1 and SI2)
|Slightly Included (SI) diamonds contain inclusions that are noticeable to an experienced grader under 10x magnification.|
(I1, I2, and I3)
|Included (I1, I2, I3) diamonds that fall in the I range contain inclusions that are obvious to an experienced grader under 10x magnification.|
Grading Gemstones -- a Brief Introduction
The Gemological Institute of America (GIA) terms by which Topazery gemstones are graded are briefly explained on this page. Like diamonds, gemstones are graded by color, cut, clarity and carat weight. When grading a gemstone, a gemologist measures a gemstone's weight in carats, and the gemstone's dimensions [length, width, and depth] in millimeters. Clarity and color are also evaluated. Color in gemstones is composed of three different qualities: hue, tone, and saturation.
Clarity Categories for Gemstones
Clarity is a gemstone's relative freedom from clarity characteristics. The clarity grade is based on how visible inclusions are and how they affect the gemstone's beauty and durability. Some gemstones tend to have more inclusions than others. For this reason, clarity ranges for gemstones are grouped into three types: Type I, Type II, and Type III. Type I stones are usually eye-clean with no inclusions visible to the naked eye. Type II stones typically show some eye-visible inclusions that don't detract from the gem's overall beauty. Type III stones are almost always included and show eye-visible inclusions.
|VVS, Eye-Clean||VS, Slightly Included||SI1-SI2, Moderately Included||I1-I2, Heavily Included||I3, Severely Included|
|Type I||The stone appears clean to the unaided eye.||Minute inclusions are difficult to see without a 10x loupe.||Minor inclusions are somewhat easy to see without a 10x loupe.||Inclusions are prominent.||Prominent inclusions have a severe impact on appearance, durability, or both.|
|Type II||The stone appears clean to the unaided eye.||Minor inclusions are somewhat easy to see with the unaided eye.||Noticeable inclusions apparent to the unaided eye.||Inclusions are prominent.||Prominent inclusions have a severe effect on appearance, durability, or both.|
|Type III||The stone appears clean to the unaided eye.||Noticeable inclusions apparent to the unaided eye.||Obvious inclusions very apparent to the unaided eye.||Inclusions are prominent.||Prominent inclusions have a severe impact on appearance, durability, or both.|
Color in Gemstones
Color is the first thing you notice about a gemstone. Color is mainly caused by the gem's selective absorption of certain wavelengths of light. Gemologists refer to this color as the gem's body color. In gemstones, color consists of three components: hue, tone and saturation.
Hue is the first impression of a color and is what you see when you first look at a gem. The GIA gemstone grading system uses 31 hues to describe color in a gemstone.
Tone is the lightness or darkness of color and ranges from light to medium to dark. Three key standards are 3 (light), 5 (medium), and 7 (dark).
Saturation is the intensity of a gemstone's color and is measured from dull to strong to vivid. The GIA uses 6 saturation measurements.
Color Hues for Gemstones
|Red-Purple or Purple-Red||RP/PR|
|strongly purplish Red||stpR|
|slightly purplish Red||slpR|
|Red-Orange or Orange-Red||RO/OR|
|Yellow-Green or Green-Yellow||YG/GY|
|strongly yellowish Green||styG|
|slightly yellowish Green||slyG|
|very slightly bluish Green||vslbG|
|very strongly bluish Green||vstbG|
|Green-Blue or Blue-Green||GB/BG|
|very strongly greenish Blue||vstgB|
|very slightly greenish Blue||vslgB|
Tones for Gemstones
Gemstone Saturation Scale
|Warm colors||Tone||Cool colors|
|slightly brownish||2||slightly grayish|
|very slightly brownish||3||very slightly grayish|
|moderately strong||4||moderately strong|