How to Know Emerald Value

Evaluating Clarity, Cut, and Size

Look for inclusions. Inclusions are any materials (such as gas bubbles or tiny crystals) that became trapped inside a stone during its formation. Almost 99% of emeralds have inclusions that are visible with the naked eye or a loupe, a jeweler’s magnifying glass. The prevalence of inclusions makes the emerald a Type 3 gemstone, which means that inclusions that can be seen with the naked eye are nearly always present. An emerald with excessive inclusions that lessen the stone’s transparency or clarity is worth less than an emerald that has fewer inclusions. Be wary of inclusions that reach the gem’s surface, as they may cause the gem to fracture.

Examine the emerald’s cut. Emeralds can be difficult to cut because the prevalence of inclusions makes them vulnerable to fracturing during the cutting process. Emeralds are often cut in a rectangular shape (known as a "step cut" or an "emerald cut") that helps the stone’s color appear consistent. An emerald’s cut should help protect the stone from potential damage from everyday wear and tear. A quality emerald cut enhances the emerald’s hue, tone, and saturation. A good cut will appear sparkly and have a desirable color, while a poor cut may have a nice color but appear dull.

Understand that emeralds come in a variety of sizes. Like most gems, emeralds can come in a wide variety of sizes, from 0.02-0.5 carat (1mm-5mm) accent gems to 1-5 carat (7mm-12mm) center stones used in rings or necklaces.

Do not equate size alone with value. It is true that larger stones are more valuable than smaller stones. However, quality is just as important as size, and large emeralds are more likely to have large or visible inclusions that may affect clarity. A smaller stone of higher quality is likely to hold more value than a larger stone with poorer quality. Additionally, a stone’s color has a significant impact on its value

Evaluating Color

Understand the importance of color. Emeralds come in a range of colors. Color is one of the most important factors in determining the value of an emerald. The variance of color in emeralds is due to differing amounts of chromium, vanadium, and iron in the environment in which the stones formed. Color can be subdivided into the categories of hue, tone, and saturation.

Identify an emerald’s hue. Hue is probably what you think of when you hear the word “color.” An emerald’s hue is its specific type of green. Emerald hues can range from bluish-green to a more yellow-green. For example, Zambian emeralds are characterized by deep bluish greens, while Brazilian and Colombian emeralds often take on a rich, pure green hue.

Look at an emerald’s tone. Tone refers to how light or dark the color of an emerald is. Emeralds can range from very light green to very dark green in tone. The association of tone and value is somewhat complicated. Darker emeralds are often considered more valuable, but if an emerald becomes too dark, it becomes less valuable. Emeralds with medium to medium-dark tones are the most valuable emeralds in the market. Emeralds with pure green or blue-green tones are the most desirable, in part because blue-green emeralds are associated with a very famous and highly-regarded gem mine in Colombia called the Muzo Mine. Be aware that emeralds that are too yellow or too blue may not be considered real emeralds and are therefore far less valuable.

Evaluate an emerald’s saturation. Saturation is tied to the gem’s transparency. Emeralds with high saturation (which means that they are highly transparent) are more valuable than emeralds with low saturation. Saturation can be tied to both inclusion and tone; very included gems can appear less transparent. Similarly, very dark green emeralds do not absorb much light, so they appear duller than lighter emeralds.

Buying an Emerald

Use a reputable jeweler. Buy valuable gems from a trusted source. Be sure that the jeweler has an established reputation. It is best to find a jeweler with a return policy for products that are sold with inaccurate descriptions of clarity and quality.

Have the gem appraised. It is a good idea to have very expensive gems (or gems that are three carats or larger) appraised by a third party. It is best to use an appraiser who holds membership in the American Society of Appraisers, one of the oldest appraisal societies in the United States. To find an appraiser, take the following steps: Search the American Society of Appraisers’ website here. Click on “find an appraiser,” then enter your zip code. Type in “gems and jewelry” in the appraisal expertise section. Select an appraiser from among the search results.

Request a report from a reputable gemological laboratory such as American Gemological Laboratories (AGL). In order to appropriately evaluate the value of an emerald that you are considering purchasing, you can request an AGL report, which identifies the type, size, cut, clarity, color, and origin of the emerald you are purchasing. This report will give you some degree of confidence as to the quality and value of your gem, even before getting a third-party appraisal.

Understand pricing. Before purchasing an emerald, you should be sure that you are getting a good quality gem for the amount of money you are spending. An AGL report will give you a starting point, but the AGL may not represent accurate market value (AGL report prices are often inflated). To get a better feel for fair pricing, you may want to shop at different jewelers, taking notes about the color, cut, and quality of each gem that you are pricing. Keep in mind that pricing a stone is ultimately subjective, so you cannot necessarily come up with a specific “formula” for the exact value of a stone.

Understand the process of oiling. Emeralds are often treated with oil or resin to improve the stones clarity. This is done because of the emeralds Type 3 nature which means its naturally included. Clarity enhancement is common practice and is considered an acceptable enhancement to the appearance of the gemstone unless it is treated with dyed oil. Emeralds treated using oil will require re-oiling every so often to maintain the stones appearance. Ask whether the emerald has undergone changes that are minor, moderate, or significant. Ask to verify this with an accredited laboratory certificate from GIA or AGL