# Diamond Glossary: 75 Terms Explained Simply URL: https://diamonds.com.lb/diamond-glossary/ · Updated 2026-10-12 This diamond glossary explains, in plain words, the 75 terms you will meet on a grading report, a stone page or a jeweller's quote: from table, crown and girdle to bow-tie, fluorescence and Triple Excellent. Each definition is short, and links to a fuller guide where one exists, so you can read our [certified loose diamonds](https://diamonds.com.lb/loose-diamonds/), compare [engagement rings in Lebanon](https://diamonds.com.lb/engagement-rings/) or [build your ring](https://diamonds.com.lb/build-your-ring/) without the jargon getting in the way. > **Quick answer:** A diamond is described by its 4Cs (cut, colour, clarity and carat), its anatomy (table, crown, girdle, pavilion, culet) and the laboratory report that grades it. Knowing a few dozen terms is enough to read any GIA or HRD report with confidence. This glossary from diamonds.com.lb defines 75 of them, A to Z. ## A ### Asscher cut A square step cut with cut corners and deep, layered facets that give a "hall of mirrors" look. Like the emerald cut, it shows inclusions and colour more readily than a brilliant cut, so a cleaner stone pays off; see our [Asscher cut guide](https://diamonds.com.lb/asscher-cut-diamond-guide/). ## B ### Bezel setting A rim of metal that wraps around the edge of the diamond instead of holding it with prongs. It is the most protective setting and has a clean, modern look; our [guide to ring settings](https://diamonds.com.lb/solitaire-halo-hidden-halo-setting-guide/) compares it with the others. ### Blemish A mark on the surface of a diamond, such as a tiny nick, scratch or polish line, as opposed to an inclusion inside the stone. Blemishes count towards the clarity grade, mostly at the top of the scale. ### Bow-tie A dark band shaped like a bow tie across the centre of some elongated diamonds, such as ovals, pears and marquises. Most elongated stones show a little; a strong one is best judged on video rather than on paper, as our [oval cut guide](https://diamonds.com.lb/oval-cut-diamond-guide/) explains. ### Brilliance The white light a diamond returns to the eye. It depends mostly on cut: a well-proportioned stone returns more light than one that is too deep or too shallow. ### Brilliant cut A faceting style with many triangular and kite-shaped facets radiating from the centre, designed for maximum sparkle. The round brilliant is the classic, and ovals, pears, cushions and radiants are brilliant cuts too. ## C ### Carat The unit of weight for diamonds: one carat is 0.2 grams, divided into 100 points. Carat is weight, not size, so how large a stone looks also depends on its shape and cut; see [how big a carat looks on the hand](https://diamonds.com.lb/diamond-carat-size-guide-hand/). ### Cathedral setting A setting in which the band rises in two arches to meet the centre stone, lifting it like the vaults of a cathedral. It gives a ring height and an elegant profile; see our [cathedral engagement rings](https://diamonds.com.lb/cathedral-engagement-rings-lebanon/). ### Certificate The common name for a diamond grading report: an independent laboratory's description of the stone's weight, measurements, colour, clarity and, for rounds, cut, with a unique report number. Every diamond we sell has a GIA or HRD report; here is [how to read a GIA report](https://diamonds.com.lb/how-to-read-gia-diamond-report/). ### Clarity How free a diamond is from inclusions and blemishes, graded under 10x magnification from Flawless (FL) down to Included (I3). Our [colour and clarity chart](https://diamonds.com.lb/diamond-colour-clarity-chart/) explains every grade. ### Cloud A cluster of tiny pinpoint inclusions inside a diamond. Most clouds are invisible to the eye; a large, dense one can make a stone look slightly hazy. ### Colour For white diamonds, how free a stone is from a yellow or brown tint, graded on the D to Z scale. Differences between neighbouring grades are subtle and easier to see side by side than on a single stone, as our [G vs H colour comparison](https://diamonds.com.lb/g-vs-h-diamond-colour/) shows. ### Crown The upper part of a diamond, between the table and the girdle. Its angles help split light into flashes of colour, the fire. ### Crystal A mineral crystal trapped inside the diamond as it formed, sometimes a tiny diamond itself. Colourless crystals are often hard to see; dark ones are more noticeable. ### Culet The point, or tiny facet, at the very bottom of the pavilion. Most modern diamonds have no culet or a very small one; a large culet can show as a dark dot through the table. ### Cushion cut A square or rectangular shape with rounded corners and softly curved sides, a classic with a romantic, vintage feel. Our [cushion cut guide](https://diamonds.com.lb/cushion-cut-diamond-guide/) covers what to look for. ### Cut grade The grade for how well a round brilliant's proportions and finish return light, from Excellent to Poor. GIA gives an overall cut grade only to standard round brilliants; read [Excellent vs Very Good cut grades](https://diamonds.com.lb/diamond-cut-grades-excellent-vs-very-good/). ## D ### D to Z scale The colour scale for white diamonds, from D (colourless) to Z (light yellow or brown), introduced by GIA. D to F are colourless, G to J near colourless, and most buyers find their best balance in the near-colourless range. ### Depth percentage A diamond's total depth, from table to culet, divided by its width. Too deep and the stone looks small for its weight; too shallow and it leaks light and looks glassy. ## E ### Emerald cut A rectangular step cut with long, parallel facets and cut corners, prized for its broad, elegant flashes of light. It shows inclusions and colour more than brilliant cuts do; see our [emerald cut guide](https://diamonds.com.lb/emerald-cut-diamond-guide/). ### Eye clean A diamond with no inclusions visible to the naked eye at a normal viewing distance. It is not a grade on any report, so it has to be judged on the stone or its video; read [why the trade buys eye-clean](https://diamonds.com.lb/eye-clean-diamonds-clarity-secret/). ## F ### Facet Each flat, polished surface on a diamond. Their number, shape and angles define the cut and decide how the stone handles light. ### Feather A small fracture inside a diamond that can look white and feathery. Most are harmless; a large one that reaches the surface, especially near a prong or an edge, deserves a closer look. ### Fire The flashes of rainbow colour a diamond throws as it splits white light into spectral colours, an effect also called dispersion. The cut controls how much fire you see. ### Flawless The top clarity grade (FL): no inclusions and no blemishes visible under 10x magnification. Internally Flawless (IF) allows only minor surface blemishes; both grades are rare. ### Fluorescence A diamond's glow, usually blue, under ultraviolet light, listed on the report from None to Very Strong. Faint or medium fluorescence rarely affects beauty, while strong fluorescence occasionally makes a stone look hazy; read [diamond fluorescence explained](https://diamonds.com.lb/diamond-fluorescence-explained/). ## G ### GIA The Gemological Institute of America, an independent, non-profit laboratory that created the 4Cs grading system and the D to Z colour scale. See our [GIA-certified diamonds](https://diamonds.com.lb/gia-certified-diamonds-lebanon/). ### Girdle The thin edge around the widest part of a diamond, where the crown meets the pavilion. It is graded from extremely thin to extremely thick; a very thin girdle chips more easily, a very thick one adds hidden weight. ## H ### Halo A ring of small diamonds set around the centre stone, making it look larger and brighter. See our [halo engagement rings](https://diamonds.com.lb/halo-engagement-rings-lebanon/). ### Heart shape A brilliant-cut diamond in the shape of a heart, with a cleft at the top and a point at the bottom. Symmetry matters more than usual, because two uneven lobes are easy to see; see our [heart-shaped diamonds](https://diamonds.com.lb/heart-shaped-diamonds-lebanon/). ### Hearts and arrows A pattern of eight hearts, seen from below, and eight arrows, seen from above, visible through a special viewer in very precisely cut round brilliants. It signals exceptional symmetry but is not a grade on the report. ### Hidden halo A row of small diamonds set under the centre stone, around its base, so it sparkles from the side while the top view stays a clean solitaire. See our [hidden halo engagement rings](https://diamonds.com.lb/hidden-halo-engagement-rings-lebanon/). ### HRD A European diamond grading laboratory and, with GIA, one of the two laboratories that certify every diamond we sell. HRD reports set out cut as three lines: proportions, polish and symmetry; see our [HRD-certified diamonds](https://diamonds.com.lb/hrd-certified-diamonds-lebanon/). ## I ### IGI The International Gemological Institute, a grading laboratory whose reports are widely used for lab-grown diamonds. Our guide to [GIA vs IGI](https://diamonds.com.lb/gia-vs-igi-diamond-certification/) explains how the two compare. ### Inclusion A natural feature inside a diamond, such as a crystal, feather, cloud or needle, formed as it grew. Inclusions are the stone's fingerprint and the basis of its clarity grade. ## K ### Karat The purity of gold, measured out of 24. 18K gold is 18 parts pure gold in 24, so three-quarters gold; not to be confused with carat, the weight of a diamond. ### Kimberley Process The international certification scheme that tracks rough diamonds between countries to keep conflict diamonds out of the trade. Read more on our [responsible sourcing](https://diamonds.com.lb/responsible-sourcing/) page. ## L ### Lab-grown diamond A diamond grown in a laboratory, with the same chemistry as a natural diamond but a different origin and a very different value over time. We sell natural diamonds only; our [honest comparison](https://diamonds.com.lb/lab-grown-vs-natural-diamonds-lebanon/) explains the difference. ### Laser inscription The report number, and sometimes a logo, inscribed microscopically on the girdle. It can only be read under magnification, so buy from a reputable dealer and [check the report number online](https://diamonds.com.lb/how-to-verify-gia-hrd-certificate-online/). ### Length-to-width ratio How elongated a fancy shape is: its length divided by its width. It changes the look on the hand, a longer oval looking slimmer and a shorter one rounder. ### Loose diamond A diamond sold unset, so you choose the stone first and the setting second. Every stone in our [loose diamond collection](https://diamonds.com.lb/loose-diamonds/) is physically in stock in Beirut. ## M ### Marquise An elongated shape with two pointed ends, like a boat. It looks large for its weight and lengthens the finger; its points are best protected by prongs. See our [marquise guide](https://diamonds.com.lb/marquise-diamond-guide/). ### Melee The very small diamonds used to decorate a ring, in halos, pavé bands and side settings. They are usually sold by size and quality in parcels rather than with individual reports. ### Milgrain A row of tiny metal beads along the edge of a band or setting, a detail typical of vintage-style rings. See our [vintage engagement rings](https://diamonds.com.lb/vintage-engagement-rings-lebanon/). ### Moissanite A lab-made gemstone that imitates diamond, with more rainbow fire and a different hardness. It is not a diamond; read [moissanite vs diamond](https://diamonds.com.lb/moissanite-vs-diamond/). ## N ### Natural diamond A diamond formed deep in the earth over an immensely long time and mined, as opposed to grown in a laboratory. Every diamond we sell is natural and certified by GIA or HRD. ## O ### Oval cut An elongated brilliant shape that looks large for its weight and flatters the finger. Watch for the bow-tie; see our [oval cut diamonds](https://diamonds.com.lb/oval-cut-diamonds-lebanon/). ## P ### Pavé A band or setting covered with small diamonds set close together and held by tiny beads of metal, so the surface looks paved with light. See our [pavé engagement rings](https://diamonds.com.lb/pave-engagement-rings-lebanon/). ### Pavilion The lower part of a diamond, from the girdle down to the culet. Its angles decide how much light comes back out through the top of the stone. ### Pear shape A teardrop shape, rounded at one end and pointed at the other, elegant and flattering on the finger. Like the oval and marquise, it can show a bow-tie; see our [pear shape guide](https://diamonds.com.lb/pear-shaped-diamond-guide/). ### Platinum A naturally white, dense and hard-wearing precious metal for ring settings. It is heavier than gold and needs no plating; compare the metals in our [ring metal guide](https://diamonds.com.lb/white-gold-yellow-gold-platinum-guide/). ### Point One hundredth of a carat. A diamond of 0.50 carat is called a "50 pointer" in the trade. ### Polish The quality of the finish on the facet surfaces, graded from Excellent to Poor. Minor polish marks are almost never visible to the eye. ### Princess cut A square brilliant shape with sharp corners, crisp and modern, with lots of sparkle. Its corners need protecting by prongs; see our [princess cut diamonds](https://diamonds.com.lb/princess-cut-diamonds-lebanon/). ### Prong One of the small metal claws that hold a diamond in its setting, usually four or six. Prongs wear with time, so they are worth having checked now and then. ## R ### Radiant cut A rectangular or square shape with trimmed corners and brilliant faceting, combining a step-cut outline with lots of sparkle. See our [radiant cut diamonds](https://diamonds.com.lb/radiant-cut-diamonds-lebanon/). ### Rapaport The trade's benchmark price list for diamonds, organised by shape, carat weight, colour and clarity. Dealers price stones as a discount from it, and our stone pages show where each one stands; read [the Rapaport list explained](https://diamonds.com.lb/rapaport-price-list-explained/). ### Report number The unique number of a grading report, usually also laser-inscribed on the girdle. Entered on the laboratory's own website, it confirms that the report is genuine and shows its details. ### Rose gold Gold alloyed with copper for a warm pink tone. The colour runs through the metal, so it needs no plating; see our [rose gold engagement rings](https://diamonds.com.lb/rose-gold-engagement-rings-lebanon/). ### Round brilliant The classic round diamond with 57 or 58 facets, cut for maximum brilliance. It is the most popular shape and the only one GIA gives an overall cut grade; see our [round brilliant diamonds](https://diamonds.com.lb/round-diamonds-lebanon/). ## S ### Scintillation The sparkle, and the play of light and dark flashes, you see when a diamond, the light or your eye moves. Together with brilliance and fire, it is what a good cut delivers. ### Setting The way a diamond is held in a ring, such as prongs, a bezel, a halo or pavé, and more loosely the ring itself without its centre stone, also called the mounting. Browse our [engagement ring settings](https://diamonds.com.lb/engagement-rings/). ### SI1 and SI2 Slightly included: inclusions noticeable under 10x magnification. Many SI1 stones are eye clean, while SI2 needs checking stone by stone, ideally on video; compare [VS2 and SI1](https://diamonds.com.lb/vs2-vs-si1-diamond-clarity/). ### Solitaire A ring with a single centre diamond on a plain or simple band, the most timeless engagement ring. See our [solitaire engagement rings](https://diamonds.com.lb/solitaire-engagement-rings-lebanon/). ### Step cut A faceting style of long, straight, parallel facets arranged like steps, as in emerald and Asscher cuts. It gives broad flashes of light rather than glittering sparkle, and shows clarity more openly. ### Symmetry How precisely the facets are shaped, aligned and placed, graded from Excellent to Poor. Very good symmetry is part of what makes a diamond look crisp and balanced. ## T ### Table The large flat facet on top of a diamond, its main window. Most light enters and leaves through it. ### Table percentage The width of the table divided by the diamond's overall width. It is one of the proportions behind a good cut, and each shape has its own comfortable range. ### Three-stone ring A ring with three diamonds side by side, usually a larger centre stone between two smaller ones. See our [three-stone engagement rings](https://diamonds.com.lb/three-stone-engagement-rings-lebanon/). ### Treatment Any process used to improve a diamond's appearance, such as filling fractures or drilling to remove a dark inclusion. Laboratories record the treatments they detect, and no stone we sell has an undisclosed treatment. ### Triple Excellent A round diamond graded Excellent for cut, polish and symmetry, often written 3EX. It guarantees precise work, though the visible difference from a top Very Good stone is small. ## V ### VS1 and VS2 Very slightly included: minor inclusions seen with some effort under 10x magnification. VS stones are usually eye clean, which makes them a popular, sensible choice; compare [VS1 and VS2](https://diamonds.com.lb/vs1-vs-vs2-diamond-clarity/). ### VVS1 and VVS2 Very, very slightly included: inclusions so small that they are difficult to see even under 10x magnification. Beautiful, but the difference from VS is invisible to the naked eye. ## W ### White gold Gold alloyed with white metals and finished with a bright rhodium plating. The plating wears gradually and can be renewed; see our [white gold engagement rings](https://diamonds.com.lb/white-gold-engagement-rings-lebanon/). ## Y ### Yellow gold Gold in its warm, natural colour, alloyed for strength. It flatters warmer diamond colours and has a classic look; see our [yellow gold engagement rings](https://diamonds.com.lb/yellow-gold-engagement-rings-lebanon/).