• February 3, 2023


What is a diamond grader?

A diamond grader is someone who determines the value of a diamond. They might evaluate important details affecting a diamond’s quality, like key physical characteristics, origin, and how it was produced.

Here are some things a diamond grader might look for when assessing the value of a diamond:

Brilliance – The brilliance of a diamond refers to how it reacts to light. The level of a diamond’s sparkling effect, called scintillation, can influence the visual appeal of the diamond. Well-cut diamonds often produce light refraction, and the amount of white light the diamond returns can affect its brightness and sparkle.

Carat – A carat is a metric diamond grader used to refer to the weight of a diamond. Typically, larger carat diamonds stay in higher demand because they’re less common, but there isn’t always a direct correlation between the weight of a diamond and its value.

Cut – The way a diamond is cut can affect how its facets interact with light. When evaluating cut, the diamond grader looks at factors like the stones’ proportions, light interactions, polish, and cut precision. Analyzing a stone’s cut can be one of the more challenging assessments for a diamond grader. 

Shape – A diamond’s shape can also affect its value. Diamonds come in a variety of specifically cut shapes. A Diamond Grader needs to understand leading trends and market changes to evaluate the effect of a diamond’s shape on its value. For e.g., round, square, emerald, heart, oval, pear, marquise, etc.

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Color – Complete transparency is the goal when graders look at a diamond. A chemically impure/low-grade diamond might contain a slight yellowish hue while some diamonds have naturally occurring colors because of the way carbon bonded during its formation.

Purity – During the stones’ formation, impurities called inclusions sometimes appear in the diamond. Graders typically score diamonds without inclusions higher than those with them. Skilled diamond cutters can sometimes manipulate the stone’s facets to remove the obviousness of an inclusion. They can also use lasers to cut out inclusions. Being able to evaluate the cutter’s skill and workmanship regarding purity is an important skill for a grader.

Origin – Where the diamond came from can also heavily affect its value. Even though their physical properties and visual appearance are identical, diamonds grown in a laboratory are often less expensive than those mined from the earth. Ethical sourcing is also a consideration for a grader.

  • Table size: Table size refers to the flat top of the diamond.
  • Girdle thickness: The girdle, or widest point of the diamond’s mid-section, can affect how the diamond interacts with light. For example, stones cut with a thin edge are less likely to cast a dark, circle-shaped shadow.
  • Pavilion depth: The pavilion is the space between the diamond’s girdle and its bottom point.
  • Star length: Star length refers to the length of the star facet. To calculate the star length, a grader has to create a percentage based on the difference between the placement of the girdle and the diamond’s table.
  • Crown height: The height of a diamond’s crown comes from the distance between the table and the girdle.
  • Crown and pavilion angle: A diamond grader also looks at the angle of the top and bottom edges of the diamond.

What does a diamond grader do?

A diamond grader evaluates the quality and value of the diamond by looking at its key physical characteristics and reviewing information about the stone. Here are some common duties of a diamond grader:

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  • Evaluate stone brilliance: When light enters through the top of a diamond, its cut surfaces, called facets, reflect the light. Many cuts can create lots of light contrast and increase the level of brilliance and sparkle graders look for.
    Communicate with jewelers, dealers, and customers: A grader often has to communicate information about diamond quality to key stakeholders.
  • Assign a value to diamonds: A diamond grader assigns a grade or value to the stone based on its weight, cut, color, origin, and purity.
  • Examine diamonds under various conditions: A diamond grader uses tools to determine the quality of a diamond. For example, holding diamonds beneath a light can reveal the level of intricacy and detail in how they’re cut to reflect light.
  • Search stones for inclusions: Inclusions are particles or contaminants present in the stone that can reduce its quality. Good cutters can manipulate light refractions or use lasers to cut inclusions away to reduce their obviousness.
  • Determine portions: A diamond grader looks at the symmetry and proportionality of diamonds.
  • Estimate stone weight: The stone’s weight, or carat, can influence value. Graders determine the carat weight of stones when analyzing quality.
  • Stay up-to-date on industry trends, knowledge, and best practices: It’s helpful for graders to stay updated on changes in diamond popularity and market trends. This can help them determine what value to assign to specific cuts, shapes, or colors.
  • Read and understand GIA reports: The Gemological Institute of America (GIA) created a universal grading system that graders can use to determine the value of a diamond. Reviewing GIA reports can give a diamond grader important information about a diamond’s history, origin, and quality.

Take a diamond grading certification course

There are several online and in-person courses available for diamond graders. GIA offers several course offerings for those interested in advancing their diamond grading knowledge. Completing a grading course and becoming a credentialed grader can boost your resume and help qualify you for positions.

Pursue a degree

While not typically required, an associate, bachelor’s, or master’s degree in a relevant field can show employers you’re an educated candidate with a well-rounded skill set. Consider pursuing a college degree in a field that can grow your knowledge and experience.

Polished Diamond Graders Course in Andheri East, Mumbai | ID: 15411687748Courses that improve skills like communication, analytical thinking, and business strategies can help you grow in your career. Here are some degrees that may benefit you as a diamond grader:

  • Fine arts: A degree in fine arts can help develop your analytical skills. Gem graders need to have excellent attention to detail and a keen eye for artistry.
  • Geology: Geology degrees help students learn more about how rocks form and the properties each. This knowledge and understanding can help you understand more about gems and how they’re made.
  • Business management: Business management degrees can be helpful for graders wanting to know more about following market trends within the diamond industry.

Diamond grader salary and job outlook

While there isn’t specific salary information available for diamond graders, the Bureau of Labor and Statistics (BLS) lists the salary information for jewelers and precious stone and metal workers as $41,900 per year. The BLS also reports that the job outlook for the industry is expected to decline by 10% between 2019-29.

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Mintly, a hiring marketplace for diamonds and gemstones, aids in providing employment to diamond graders and related roles in various jewelry and gemstone stores in India, UAE, and the USA.

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