As you look for a diamond, you’ll come across quite a bit of jewelry industry terminology. And if you’re not a jeweler or a gemologist, all these new terms can be very confusing. It’s important to understand diamond terminology if you want to make an educated decision when buying a diamond, but having to constantly look up words and phrases can be a huge headache. So, to help you keep things moving along smoothly as you shop for a diamond, we’ve drafted up this master list of diamond terminology explanations. Keep this list handy as you shop, check these definitions as needed, and find your perfect diamond with ease.
The 4Cs of Diamonds
The 4Cs of diamonds, also known as simply the 4Cs, are diamond cut, diamond color, diamond clarity, and diamond carat weight. These are four diamond qualities that you’ll find on every diamond’s grading report. The 4Cs, created by the Gemological Institute of America (GIA), are essentially a standardized way of looking at a diamond’s qualities. Once you understand carat weight and cut, color, and clarity gradings, you can tell a great deal about the way a diamond looks just by viewing its grading report.
Diamond cut is a grading of how well a diamond has been cut into its shape. Most jewelers and gemologists agree that diamond cut is the most important of the 4Cs. This is because how well a diamond has been cut has an enormous impact on the diamond’s shimmer and, therefore, its beauty. If a diamond has been cut well, it will capture and reflect light beautifully. If a diamond has a subpar cut, it will look dull, dim, and lifeless.
Because cut is so important to a diamond’s beauty, diamond experts generally recommend that shoppers prioritize cut grade when they look for a diamond, often suggesting that they select a diamond with a cut grade of either Very Good or Excellent.
Diamond color is a grading of how colorless a diamond is. Colorless diamonds (also sometimes called “white diamonds”) can vary in how colorless they are, going from absolutely colorless to noticeably yellow. This range in diamond color is graded on a scale of D to Z, with D color diamonds at the colorless end of the scale.
Diamond clarity is a grading of how flawless a diamond is. Diamonds can have external flaws, which are called blemishes, and internal flaws, which are called inclusions. Diamond clarity grades are assigned based on the amount and location of a diamond's flaws, and how easy it is to see a diamond’s flaws under various levels of magnification.
Carat is a weight measurement that is used to measure diamonds and other gemstones. Diamond carat weight can give you a general idea of a diamond’s size, since diamonds that weigh more will be larger. Note, however, that some diamond shapes will look larger per carat than others due to how their surface area is distributed.
Diamond shape is commonly confused with diamond cut. However, these two terms refer to very different things. Diamond cut is a quality grading that can tell you how well a diamond was cut. Diamond shape, on the other hand, is just what it sounds like: the shape a diamond has been cut into. Examples of diamond shapes include round, oval, and princess cut.
Fancy shaped diamonds, also called fancy cut diamonds, are diamonds that aren’t round cut. Round diamonds are the most popular among all diamond shapes, so they stand in a category of their own. Then, all other diamond shapes fall into the fancy shaped category. Examples of fancy shaped diamonds include princess cut, oval shaped, heart shaped, pear shaped, marquise cut, trillion cut, emerald cut, cushion cut, and radiant cut diamonds.
A diamond grading report is a document that features a record of a diamond’s qualities, including its cut grade, color grade, clarity grade, and carat weight. Grading reports are done by gemological laboratories, such as the GIA, the AGS, and EGL USA.
Terms Describing Sparkle: Brilliance, Fire, Scintillation
There are three terms that are commonly used to describe the nuances in a diamond’s sparkle:
Brilliance: The white light emitted from a diamond.
Fire: The rainbow-colored light emitted from a diamond.
Scintillation: The pattern of bright and dark areas caused by reflections in a diamond when it is moved.
Diamond dispersion is essentially how a diamond creates its fire. When white light enters a diamond and is broken into colored light, this is dispersion.
Fluorescence is the glow that some diamonds emit under ultraviolet light. Around 30% of diamonds have fluorescence, which usually looks bluish, but may look yellow or orange.
Fluorescence is considered a property of a diamond, rather than a quality, since fluorescence is not inherently good or bad. Fluorescence can improve the appearance of a diamond’s color, make a diamond look hazy, or have absolutely no effect on a diamond’s appearance when it is not under UV light. You can find information about a specific diamond’s fluorescence on its grading report.
Table is the term for the flat surface on the very top of a diamond, which is a diamond’s largest facet. A diamond’s table is what faces outward when a diamond is set in jewelry.
Culet is the term for the bottom tip of a diamond. A diamond’s culet may be pointed or it may feature a single polished facet that is parallel to the top of the diamond. This extra facet is meant to help prevent damage to the point. Culet size is something that affects a diamond’s cut grade, since a large or poorly placed culet facet can have a negative impact on a diamond’s appearance and ability to capture light.
Brilliant cut refers to a certain way of faceting, or cutting, a diamond. Brilliant cut diamonds feature numerous tiny facets that are designed to maximize the brilliance of the diamond to the fullest extent.
Some examples of common diamond shapes that feature brilliant cuts include round brilliant cut diamonds, princess cut diamonds, oval cut diamonds, marquise cut diamonds, cushion cut diamonds, pear shaped diamonds, and radiant cut diamonds.
Step cut refers to a certain way of faceting a diamond. Step cut diamonds feature long, linear facets that are arranged in parallel lines, so they look much like steps. Step cut diamonds reflect light differently compared to brilliant cut diamonds. Instead of giving off a shimmery look, step cuts reflect light in larger flashes.
Some examples of common diamond shapes that feature step cuts include emerald cut diamonds, asscher cut diamonds, and baguette cut diamonds. Note that if you’re thinking of purchasing one of these step cut diamond shapes, you may want to consider prioritizing your diamond clarity grade. It’s easy to see inside a step faceted diamond, so flaws are more obvious on a step cut diamond than they are on a brilliant cut diamond.
Eye clean is a term that may be used when describing a diamond’s clarity. If a diamond doesn’t have any flaws that can be seen with the naked eye, it's what’s known as eye clean. The term eye clean is usually only used to describe diamonds that don't have flaws that are noticeable to the naked eye, but do have flaws that can be seen with a jeweler’s loupe or other types of magnification.
Face Up White
Facing up white is a term that may be used when describing a diamond’s color. This term is usually used to describe diamonds that have lower color grades, yet look white when viewed from above. Therefore, they “face up white.”
You may sometimes see a diamond that’s referred to as a natural diamond, an earth-created diamond, or a mined diamond. This means that the diamond formed naturally on its own and that it was not man-made.
Laboratory-grown diamonds have the same chemical, physical, and optical properties as natural diamonds. However, they are different from natural mined diamonds because they were made in a lab by scientists, rather than by nature in the earth. Lab-grown diamonds will usually be made using one of two methods:
High Pressure High Temperature (HPHT): When using the HPHT creation method, scientists expose a diamond crystal seed to intense heat and pressure in order to cause a diamond to grow around the seed.
Chemical Vapor Deposition (CVD): When using the CVD creation method, scientists place a diamond seed in a chamber with carbon-rich gasses and heat up the chamber, causing a diamond to grow around the seed.
A rough diamond, also called a raw diamond, is a natural diamond gemstone that hasn’t yet been processed with cutting or polishing. Raw diamonds that haven’t been touched by man look much like pieces of broken glass. It takes the work of an expert diamond cutter to turn a rough diamond into a faceted, polished diamond that has beautiful brilliance.
Have any questions about diamond terminology? We’re always happy to share our knowledge of diamonds, gemstones, engagement rings, wedding bands, and other types of jewelry. You can reach out with your questions by speaking with one of our expert team members when you visit our showroom or by emailing us at email@example.com.