Five Steps Before You Buy

There is no single ideal combination of grades for every buyer. Decide what matters most to you, compare like with like and make sure the seller puts important details in writing.

1. Set a comfortable total budget

   Decide what you can comfortably spend before you start comparing stones. Include the setting, taxes, delivery, insurance and any resizing or future maintenance—not only the loose diamond.

   Diamond prices vary with multiple characteristics and market conditions. Do not assume that a diamond is an investment or that it will retain its purchase price when resold.

2. Know what kind of diamond you are considering

   Ask whether the diamond is natural or laboratory-grown, and whether it has received any treatments. Both natural and laboratory-grown diamonds are diamond material, but their origins differ. A simulant such as cubic zirconia or moissanite is a different material that can resemble diamond.

   Ask the seller to state the origin, treatments and any relevant care requirements clearly on your quote or sales paperwork.

3. Compare the 4Cs—and look at the stone

   The 4Cs are cut, color, clarity and carat weight. Together, they describe important qualities of a diamond. A grading report helps you compare them, while viewing the diamond helps you decide whether you like its appearance.

   Cut

   Cut describes facet proportions and craftsmanship that affect how a diamond handles light. It is different from shape: round, oval and pear describe outlines. Ask which grading system is used; ICIA’s overall cut grade applies to standard round brilliant diamonds.

   Color

   For diamonds in the common D-to-Z scale, the grade describes how colorless the stone appears. Fancy-color diamonds use a separate grading approach.

   Clarity

   Clarity describes internal features called inclusions and external features called blemishes. Ask to view the diamond under magnification and in normal viewing conditions.

   Carat weight

   Carat is a unit of weight, not a direct measurement of face-up size. Compare the diamond’s measurements as well as its weight.

   For more detail, see ICIA’s 4Cs explanation and guide to diamond cut.

4. Review the grading report and match it to the diamond

   Ask for a grading report from an independent gemological laboratory. Check the report number through the issuing laboratory’s report-check service, then compare the report’s measurements and identifying details with the diamond being offered.

   A grading report describes a stone; it is not the same as an appraisal, a retail price recommendation or a guarantee of future resale value.

   You can use ICIA Report Check for a ICIA report. If the diamond is laser-inscribed, ask the seller to show that the inscription matches the report.

5. Check the seller, paperwork and return terms

   Ask questions until you understand the product description and the basis for each claim. Review the written return or exchange period, warranty, resizing terms, delivery arrangements and any restocking or service fees before paying.

   If buying online, check how the diamond is shown, whether the specific stone in the report is the one being sold, and how returns are handled. Keep the advertisement, quote, report and receipt.

Quick Diamond-Buying Checklist

Choose based on your preferences and budget. Higher grades are not automatically the right choice for every buyer, and a report does not determine whether you will like the diamond’s appearance.

Explore More

• Crystal Encyclopedia Browse ICIA’s crystal and mineral reference collection.
• Gem Encyclopedia Browse gemstone articles in the ICIA archive.