Houston Jewelry Appraisal and Repair

Colored Stone Clarity

STONE TYPES AND CLARITY FACTORS

COLORED STONE CLARITY

Inclusions like cavities, large feathers, and crystals can greatly devalue a colored stone because they largely affect its color saturation and brilliance. Gemstones are always cut to preserve carat weight. Because of this,
some feathers break the surface of the stone. These surface reaching feathers can cause the gemstone to cleave; or break apart if accidently struck on something during wear. They are very delicate.
Should anyone purchase a gem with these features, it should be disclosed to the customer. This way they know to be gentle with the stone.

THE THREE GEMSTONE TYPES

Certain minerals inherit more inclusions than others.
The gemstone is identified, and graded according to three Types:

Type I: Gems are normally eye-clean with little to no inclusions visible to the unaided eye.
(Aquamarine; Morganite; Golden Beryl; Green Tourmaline; Blue Topaz; Zircon; and Tanzanite)

Type II: Stones commonly consist of slight inclusions that are not so obvious to the naked eye.
(Alexandrite, Corundum, Certain Garnets; Iolite; Peridot; Spinel; Quartz; all Tourmaline colors)

Type III: Gemstones are, for the most part, almost always naturally included. The major of these stones contain Fractures and Crystals of different minerals. There are three varieties. These varieties are typically fracture filled.
(Red Beryl and Emerald (both filled with Oils and Resins); Watermelon Tourmaline; can be filled, not regularly)

FIVE FACTORS OF CLARITY

Alongside diamond, the Five Factors of Clarity are also applied to in order to categorize stones.
The Factors are key to sorting gems within the appropriate category.

1) Size of the Inclusion

2) Location of Inclusions

3) Relief (or) Contrast of the Inclusion
4) Number of Inclusions

5) Nature of the Inclusion

All parts equally*

GIA Size Clarity Factor Large Feather in Gemstone

Size of the Inclusion- Is the inclusion large and obvious, or small and minor in size?

GIA Location Clarity Factor Feather under the Table of the Emerald Gemstone

Location of Inclusions- Is the inclusion within the center of the gem or off to the side?

GIA Relief Clarity Factor Black Crystals in the Blue Sapphire

Relief (or) Contrast of the Inclusion- Is the inclusion dark or does it somewhat blend in with the stone?

GIA Number Clarity Factor Many crystals and feathers in an Emerald

Number of Inclusions- A large number of different clarity characteristics can have a negative effect. How many inclusions are in the stone?

GIA Nature Clarity Factor Large durability issue in a Blue Sapphire Weak Cleavage Plane

Nature of the Inclusion- Does the inclusion type impact the gem’s durability?

Remember, Clarity Grades for Colored Gemstones are both, graded and classified differently from Diamond.

When grading, the stones are first carefully examined under the microscope. All clarity characteristics are identified. Once done, the gemologist will give it one last look under the jeweler's loupe knowing where the inclusions are.

The gemstone is then graded and assigned a grade with no magnification.

CLARITY GRADES AND THEIR DESCRIPTIONS

Here are the Five Grade Categories

TYPE II: PADPARADSCHA SAPPHIRE SAMPLE

Eye Clean (EC): When seen with the naked eye, the Gemstone is free of Inclusions

Lightly (Slightly) Included (LI): Minute, Minor, and Noticeable inclusions difficult, somewhat easy, and apparent to see with the unaided eye.

Moderately Included Clarity Grade Sapphire

Moderately Included (MI): Minor, Noticeable, and Obvious inclusions somewhat easy, apparent, and very apparent to see with the unaided eye.

Heavily Included (HI): Prominent inclusions; negative effect on appearance (or) durability

Severely Included Clarity Grade Sapphire

Severely Included (SI): Prominent inclusions; severe effect on appearance (and) durability

Jewelry Artisan • Gemologist • Designer