How to Choose a Blue Diamond

Blue diamonds differ from other blue gemstones in sheer brilliance. The chemical makeup of diamonds is unlike any other stone, and when properly cut, diamonds can outshine any sapphire, topaz or tanzanite gem. Blue diamonds are quite rare, and often enhanced for color. They are stunning alone or with other colored diamonds or stones, as rings, necklaces, pendants and bracelets. Determine whether a blue diamond's value matches its sticker price.

Difficulty: Moderate

Instructions

Form Purchasing Criteria

1. Decide how important color originality is to you. Many diamonds are heat- and pressure-treated to enhance color, an accepted process in the trade that nonetheless lowers the stones' value. Diamonds with original blue color are rare and therefore more costly.

2. Choose whether to buy loose stones and have them set or view diamond jewelry items and buy preset pieces.

3. Decide on a spending limit. The color of blue diamonds already puts them in a higher price range than colorless diamonds, so base the rest of your budget decision on carat weight (size), then clarity and then setting.

4. Choose whether to buy from a reputable dealer with less guesswork but possibly higher prices or a discount vendor who may or may not be able to provide adequate documentation of authenticity.

View and Choose a Blue Diamond

5. Examine a diamond for color. Choose a "fancy" blue that expresses consistent color and brilliance across its full surface, unmarred by dark pockets.

6. Ask your dealer to display the diamond in different light settings. For jewelry or stones that you plan to set, use a mirror and view them against your skin coloring.

7. Compare the shapes of different cuts of blue diamonds to see which will best suit your purpose. Round or square facet cuts reflect light much differently than the rectangular emerald cuts.

8. Compare your favorite loose stones or jewelry pieces and let clarity be the deciding factor. It is the clear, blue brilliance of a diamond that most determines its value.

Tips & Warnings

• "Fancy" is not just a term to justify a higher price. Diamonds are graded for color on a scale of colorless, or clear, to fancy, or richly colored.
• Very dark blue diamonds can look black in some light. If this is not the effect you wish, view the diamond in very low light to be sure you get the effect you desire.
• Ask your dealer about the refund clause before you make a significant investment on a blue diamond. Be sure that it gives you enough time to get a third-party appraisal or change your mind and return the stone.