Carat weight

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Shape & Cut

Describes the geometrical form of the gemstone and the Cut style of the facets.

• Common shapes are round, oval, pear, cushion, marquise, rectangular etc.
• Cut styles can be step or brilliant or combinations of these and cabochon. In specific cases a “Cut Quality Grade” will be included in the report.

Shape & Cut

Represents the mineralogical “family” of the gemstone (corundum, beryl, quartz, zoisite, tourmaline, etc.). All members of the species share the same optical and physical properties.

Variety

Represents each member of the species based on a difference in color or phenomena. Examples. a red Corundum is a Ruby, a blue Beryl is an Aquamarine, a color change Chrysoberyl is an Alexandrite.

Transparency

It represents the ability of the gemstone to transmit light. The grade depends on the internal characteristics of the gemstone, presence of inclusions, feathers, fissures or the nature of it as a single crystal or an aggregate.

Color

It is the visual appearance of the gemstone and is the result of its three components- hue, tone and saturation.

• The Hue is the tinge position on the visible spectrum (from red to violet). Could be a “pure” color or composed of two or more components (Example- pleochroic gemstones, multicolored gemstones).
• The Tone is about how light or dark the tinge is from light, medium to dark.
• The Saturation is the intensity of the Hue (very light, light, intense, deep, vivid).

Gemologists use a combination of the 3 components to define a color.

• Example 1: A greenish blue sapphire with an intense saturation, along with a dark tone, will be Deep Greenish Blue.


• Example 2: A pink spinel with a low Saturation and light Tone will be described as Light Pink Spinel.

Enhancements & Treatments

Indicate if the gemstone exhibits the presence of an artificial process applied to it by humans. The objective is to improve the color or its transparency or both. Enhancements & Treatments are commonly used in the trade for most gemstones of commercial qualities. Different methods are used for different gemstones.

Color Treatments

• H: It means Heated. The stone exhibits indications of Heat treatment (ex. Sapphires, Rubies)
• D: “Ti” Diffused. The stone has been treated by Heating process and surface Diffusion of foreign chemicals (Titanium), to induce or drastically improve the color intensity (Commonly found in Sapphires).
• T: “Be” diffused. The stone has been treated by Heating process and deep diffusion of foreign chemicals (Beryllium), to induce or drastically improve the color intensity (Commonly found in Orange Sapphires).
• I: Irradiated. The stone has been color treated by irradiation followed by a heating process to modify and stabilize the color (commonly found in. Blue Topaz).
• SC: Surface Coating. The stone exhibits indications of color treatment by the application of a thin layer of coating on the pavilion surface (ex. Pink Topaz).

Clarity Treatments

• C: the stone exhibits indications of clarity enhancement with presence of foreign substance (oils or resins) in internal fissures (commonly found in Emeralds). It is graded as Minor, Moderate or Significant evidence.
• Ha or Hb: It means that the stone exhibits indications of Heat treatment with presence (minor (Ha) or major (Hb) of foreign substance in internal fissures due to the heating process (commonly found in Rubies).
• G: Clarity treated. The stone exhibits indications of Heat treatment with significant presence of foreign substance (lead glass) in internal fractures commonly found in Rubies).
• Gc: Clarity & Color treated. The stone exhibits indications of Heat treatment with significant presence of foreign substance (Cobalt-doped glass) in internal fractures (commonly found in Sapphires).
• N: It means that the stone does not have any indication of enhancement/treatment. These stones are rare and highly valued.

Origin

It is possible in some cases to determine the geographic origin of the gemstone mostly for Ruby, Sapphire & Emerald.
This is considered as an opinion of the gemologist, after reviewing the gemological and spectrographic characteristics of the stone.