How To Buy A Loose Diamond

Welcome to Plateau Jewelers, nestled in the heart of Sammamish, WA. Buying a loose diamond is a significant investment that requires careful consideration and research and purchasing a loose diamond can be an exciting yet daunting experience. With our expertise, you'll learn how to navigate the complexities of choosing the perfect diamond, from understanding the 4Cs to making an informed decision that aligns with your style and budget.

The Importance of the 4C´s when Buying a Loose Diamond

When buying a loose diamond, the 4C's—Cut, Color, Clarity, and Carat Weight—are crucial factors to consider. These characteristics determine a diamond's quality and overall appeal. This guide will provide insights and tips to help you make an informed decision.

Cut Quality

  • Beyond the Grade: While the cut grade is a good starting point, understanding the proportions, symmetry, and polish of the diamond is crucial for assessing its true brilliance and fire.
  • Fancy Shapes: For fancy-shaped diamonds, such as ovals or marquises, cut grades are not always standardized. Pay attention to the length-to-width ratio and the overall symmetry to ensure a pleasing appearance.


  • Undertones and Hue: Diamonds can have subtle undertones that affect their overall look. Consider the hue of the diamond under different lighting conditions to ensure it meets your expectations.
  • Setting Impact: The metal color of the setting can influence the perceived color of the diamond. A yellow gold setting can make a diamond appear warmer, while a white gold or platinum setting can enhance its brightness.


  • Location of Inclusions: The position of inclusions can impact a diamond's appearance. Inclusions near the edges might be hidden by the setting, while those in the center can affect transparency.
  • Type of Inclusions: Not all inclusions are created equal. Feathers, clouds, and pinpoints have different impacts on a diamond's clarity and should be evaluated individually.

Carat Weight

  • Price Jumps: Prices of diamonds can increase significantly at certain carat weights (e.g., 0.5, 1, 1.5 carats). Consider slightly under or over these popular weights to find better value.
  • Spread vs. Depth: A diamond with a larger spread (surface area) may appear larger but could lack depth, affecting its brilliance. Balance is key.

Setting Your Budget

Before you start shopping, determine your budget. This will help you focus on options that offer the best value within your price range.

Choose the Right Shape

Diamonds come in various shapes, including round, princess, oval, marquise, emerald, and cushion. Each shape has its unique characteristics and appeal. Choose a shape that aligns with your personal style and the design of the jewelry piece you have in mind.

Diamond's Certification

Ensure that the loose diamond comes with a report from a reputable grading organization, such as the Gemological Institute of America (GIA) or the American Gem Society (AGS). This report provides an unbiased assessment of the diamond's quality.

Shop from a Reputable Dealer

Choose a reputable dealer with a proven track record of quality and service. A trustworthy dealer will provide detailed information about the diamond, including its grading report, and offer a return policy or guarantee.

Inspect the Diamond in Person

If possible, inspect the diamond in person under proper lighting. This will allow you to evaluate its brilliance, fire, and overall appearance. Ask the dealer to show you the diamond under a gem microscope to examine it for any inclusions or imperfections.

Compare Prices and Quality

Compare prices and quality across different dealers to ensure you're getting the best value for your money. Don't be afraid to ask questions and seek clarification on any aspects of the diamond you're unsure about.

Consider Future Resizing and Setting

Keep in mind that the diamond will eventually be set in a piece of jewelry. Consider the type of setting you want and whether the diamond's shape and size are suitable for that setting. Also, think about the possibility of future resizing, as this can affect your choice of diamond and setting.

Get an Appraisal

Once you've purchased a loose diamond, consider getting it appraised by an independent gemologist. This appraisal will provide you with an official valuation of the diamond and can be useful for insurance purposes.


In the quest for the perfect loose diamond, knowledge is your most valuable tool. At Plateau Jewelers, we pride ourselves on providing not just exquisite diamonds but also the expertise and guidance you need to make an informed decision. Whether you're creating a custom piece or selecting from our collection of beautiful mountings, we're here to ensure that your diamond buying experience is as dazzling as the gem itself. Visit us in Sammamish, WA, and let's turn your diamond dreams into reality.