Diamond Cut

Data from GemFind’s 2018 Semi-Annual Diamond Click Trends Report reveals that while the industry might have resisted the idea of a diamond cut grade, consumers love it.  According to the report, online consumer searches for diamond cut grade of “excellent” garnered more searches than color, clarity, shape, or size.


So what is diamond cut grade?  A diamond cut grade refers to the diamond’s proportions, symmetry and polish.

The diamond cut affects:

  • Brilliance (the brightness created by the combination of all the white light reflections from the surface and the inside of a polished diamond)
  • Fire (the dispersion of light into the colors of the visible spectrum, seen as flashes of color)
  • Scintillation (the flashes of light and dark, or sparkle, when a diamond or light source is moved).

A diamond cut grade provides a single rating which weighs all factors on a diamond’s visual performance, making it a vital tool in grading and rating a diamond.

Cut grade should be a key consideration when evaluating a diamond.




Gemological Science International (GSI) is an independent commercial gemological laboratory. We combine state-of-the-art technology with deep professional expertise.

GSI provides reliable, fast, and professional gemstone identification as well as grading and appraisal services to the global fine jewelry industry. GSI is the only major gemological laboratory established in the 21st century. Within a relatively short period of time, GSI has grown to become one of the largest gem labs in the world.

In recent years, GSI has expanded its global footprint by opening offices in the United States, India, Israel, Belgium and Botswana. From New York City to Antwerp and Mumbai, GSI works in close proximity to our clients in jewelry manufacturing, fabrication and distribution. GSI’s goal is to make gem lab services as reliable and convenient as possible for leading companies in the gem and jewelry trade.

GSI offers several grading reports to meet client needs for different levels of format, detail and price.  Each report includes educational materials to help consumers understand the information in the context of personal jewelry and diamond purchases.

All GSI Reports include:

  • Guide to Understanding Your GSI ReportClick here to read it interactively
  • How to Take Great Care of Your Gems and Jewelry
  • Information about our Virtual Vault for U.S. customers
  • Terms & Conditions

Please note that all GSI Reports can be customized to meet specific client needs.

  1. The Full Diamond Examination Report (FDX Report) is an 8.5″ x 11″ document, summarizing GSI’s most comprehensive service for identifying and grading an individual gemstone or piece of jewelry, including materials and side stones.  Click here to access Understanding Your FDX Report, a concise explanation of all terms used in the report, written in consumer-friendly language.

    In addition to documenting many details, FDX includes plotting diagrams, showing internal inclusions and external blemishes. Our customers have several options for customizing the format and contents of their FDX Report to their needs. For example, some reports contain a photo of the stone or jewelry items, as well a diagram. Others may include a gemstone profile with dimensions.

    Click here to see the inside back cover, with an interactive version of our Guide to Understanding the Report.

  2. The Intermediate Diamond Examination Report (IDX Report) is a more compact report that may include a photo or diagram, and may also be modified and customized to meet specific customer needs.

    View a sample IDX Report.

  3. The Modified Diamond Examination Report (MDX Report), is a convenient credit-card-sized document containing basic information about a gemstone.

    View a sample MDX Report.

  4. Trade Consultation ReportThis compact folding report, designed for trade use, includes the plotting diagram and basic gemstone information.
  5. Hearts and Arrows ReportThe Hearts and Arrows concept began in Japan in the 1980’s. To achieve a repeatable and gradable hearts and arrows pattern, the diamond should be cut to very precise proportions. The most important factor is the cut. which produces symmetrical hearts and arrows.Our Hearts and Arrows grading report documents that the cut quality and gem dimensions meet these exacting standards.
  6. Light Performance PSX ReportOn one convenient report, integrated with the 4C’s, GSI provides a total view of each diamond’s most important characteristics including cut, clarity, color, carat weight and all five light performance properties:
    1. Brilliance…the intensity of the reflection of white light from the diamond’s surface to the eye.
    2. Fire…the amount of color that a diamond returns to the eye, including intensity and dispersion.
    3. Scintillation…the diamond’s property of flashing splashes of moving light across its surface.
    4. Contrast effect…the intensity variation between light and dark areas across the diamond’s surface.
    5. Efficiency…the portion of a diamond’s surface that reflects light back to the eye.