Diamonds on Web Glossary Shop Diamonds on Web >  

A|B|C|D|E|F|G|H|I|J|K|L|M|N|O|P|Q|R|S|T|U|V|W|X|Y|Z

GIA - Gemological Institute of America:
The Gemological Institute of America, or GIA, is one of the oldest gemology institutes and has set the standards for diamond grading around the world. A diamond grading report issued from the GIA documents key diamond characteristics, and is signed by a leading gemologist.

What your GIA diamond report covers:
 

GIA Report Number: Unique GIA Report identification number registered in GIA's extensive global database.

Date: Data GIA Report was issued

Laser Inscription Registry: At your request, a diamond may be micro-laser inscribed with its unique GIA Report number.

Shape & Cutting Style: Description of the outline of the diamond (shape) and the pattern on the facet arrangement (cutting style).



 
  • Measurements: The dimensions of the diamond listed as "minimum diameter - maximum diameter x dept" for round shapes and "length x width x depth" for fancy shapes.

  • Weight: The weight of the diamond given in "carats". One carat is equal to 1/5 of a gram. In keeping with the internationally recognized trade practice, weight is recorded to the nearest hundredth of a carat.



Proportions: This section describes several characteristics relating to the diamond's cut.



 
  • Depth: The depth of the diamond relative to the average diameter for round shapes, or the width for fancy shapes.

  • Table: The average size of the table facet in relation to the average diameter for round shapes, or the width of the table in relation to the width of the diamond for fancy shapes.

  • Girdle: The thickness of the girdle relative to the size of the diamond, and condition (polished or faceted) if applicable.

  • Culet: The size of the culet facet relative to the size of the diamond.

  • Finish: Finish grades represent the quality of the surface condition (polish) and the size, shape and placement of the facets, including the evenness of the outline (symmetry).



Clarity Grade: Represents the relative absence of inclusions (internal characteristics) and blemishes (external characteristics). Clarity is graded on a relative scale from Flawless to Included based on size, nature, position and quantity of clarity characteristics visible under 10x magnification.

Color Grade: Assesses the absence of color from colorless to light yellow, brown or gray when compared to GIA Master Color Comparison Diamonds (see GIA Color Grading Scale).

 
  • Fluorescence: The strength and color of the diamond when viewed under long-wave ultraviolet light such as is present in daylight.



Comments: Comments describe additional identifying characteristics or features that are note represented on the report or Dossier.

Additional Inscription: At your request, diamonds may be micro-laser inscribed with a brand name, a trade name or a personal message. These appear either in the "Additional Inscription" section or in the "Comments" section and become part of our laser inscription registry.

GIA Clarity and Grading Scales: These scales illustrate the GIA COlor and Clarity grades and their relative positions in the GIA Diamond Grading System.

Diagram/ Plot: A diagram that approximates the shape and cutting style of the diamond is included on every Diamond Grading Report. Symbols on the diagram indicate the type of nature, position and approximate size of a clarity characteristic.

Key to Symbols: Lists the characteristics and symbols shown on the diagram, if present.

Security Features: To ensure integrity, GIA Gem Trade Laboratory Reports include a suite of security components. Notable features include a hologram, security screen, microprint lines and chemical sensitivity, in addition to several other proprietary security features.