Four C's of diamond quality

The most important criteria in selecting a diamond are the 4Cs; color, clarity, carat, weight and cut. Each of these factors has an impact on the quality and price of a diamond. Learning about the 4Cs will give you a basis from which to evaluate different diamonds and compare prices. Buying a diamond is a very personal decision; you decide which of the 4Cs is most important to you.

Color

Diamonds are classified by the degree of color they contain. The most valuable; and rarest diamonds are completely colorless. While most diamonds may appear colorless to the naked eye, they often contain traces of other colors.

A color scale established by the Gemological Institute of America (GIA) assigns a letter to the degree of colorlessness found in a diamond. Beginning with D and ending with Z, each descending letter denotes an increasing amount of light yellow, brown or gray in the diamond.

• E, F: Only a gemologist can identify the minute traces of color found in these diamonds. The stones appear colorless.
• G, H, I: Nearly colorless. Diamonds in this category have a slight color, but it is not noticeable to the untrained eye.
• J, K, L: Faint traces of color are visible when the diamond is looked at face up.
• M – Z: Obvious color is apparent to even the untrained eye in whatever position the diamond is viewed.

Clarity

Almost all diamonds contain slight impurities. Often invisible to the naked eye, these natural “birthmarks” fall into two categories; inclusions, which are internal, and blemishes, which are external. Inclusions can be the result of trace elements or minerals that were trapped as the stone was formed. These identifying characteristics are unique to each diamond and may appear as feathers, clouds or crystals. Blemishes may be visible on the diamond’s surface, such as scratches or chips.

The fewer the impurities, the more valuable the diamond will be. Since most inclusions are only visible under powerful magnification, higher clarity does not necessarily mean that the diamond is more beautiful than a stone of a lesser clarity. But it will make a difference in terms of how the diamond is priced.

The GIA established a grading system to measure the type and size of these imperfections.

• FL, IF: Flawless, Internally Flawless. There are no inclusions, internal flaws, blemishes, or external flaws.
• VVS1, VVS2: Very, Very Slight Inclusions. It is very difficult to see inclusions under 10x magnification. An excellent quality diamond.
• SI1, SI2: Slight Inclusions. Inclusions are visible under 10x magnification and may not be visible to the naked eye when the stone is in the face-up position. A good diamond value.
• I1, I2, I3: Obvious inclusions, which are visible to the naked eye.

Carat Weight

The carat weight is the standard unit of weight for a diamond. The word carat is derived from the word for the carob tree, whose tiny seeds were known for their uniformity and consistent weight. Diamonds were weighed using carob seeds as a measure. In Asia, rice was used to measure diamonds.

A diamond that equaled four grains of rice weighed 1 carat.

• One carat is the equivalent of 0.2 grams
• One carat is also divided into 100 points.
• Points are generally used to describe increments of weight within a carat.
• The weight of a 3/4-carat diamond can be shown as .75 carats or 75 points.

Carat refers to weight and not size. A 1-carat diamond will not be the same size as a 1-carat sapphire, due to the density of the gemstone material. Weight affects price. While a 1.00 carat stone weighs twice as much as a .50 carat diamond, the larger stone is actually more than twice as valuable because it is rarer. In higher quality diamonds, the price rises as the size increases.

Cut

Cut refers to the arrangement of facets on the stone, which in turn determines the diamond’s radiance. Often considered the most important of the 4Cs, it is also the only category where human skill; rather than nature, affects both the beauty and cost of a diamond. The diamond cutter follows precise mathematical proportions that relate to the height, width and depth of the crown (top), girdle (widest part) and pavilion (bottom). When a diamond is cut to proper proportions, light is reflected from one facet to another and then dispersed through the top of the stone, resulting in a burst of fire and brilliance. Fire refers to the flashes of color you see when you look at a diamond; brilliance is its sparkle.

Ideal Cut

In 1919, Belgian diamond cutter Marcel Tolkowsky created the mathematical formula for the “ideal” cut by devising the optimum combination of angles that would maximize the amount of light that entered and would then be reflected back out. Ideal cut diamonds can be more expensive because of the skill and time involved in cutting the diamond.

Cutting Styles

Cutting styles include brilliant cut, step cut or mixed cut.

• Brilliant cut is designed to maximize brilliance. It has 58 facets; 33 on the table (top), 24 on the pavilion (bottom) and the culet (the bottom point). In this cut, all 58 facets appear to radiate from the center out through the top of the diamond.

• Step cut resembles stair steps because three concentric rows of facets are arranged around the table, the pavilion and the culet. The emerald cut is an example of a step cut diamond.
• Mixed cut combines elements of both the brilliant and the step cuts. For example, the crown may be cut as a brilliant cut and the pavilion as a step cut.

Cuts range from ideal to poor. A poor cut diamond, for example, may be cut too deep or too shallow. In a diamond that is cut too deep, light is reflected through the sides and the center of the diamond may appear dark. A shallow cut diamond allows light to escape from the bottom and makes the table appear dull. Too shallow a cut gives the appearance of a black hole, referred to by industry insiders as a “fish eye.”

Always consult an expert certified gemologist before investing in a diamond. To speak with an expert call or email (561) 716-0377, Info@MatthewGreenJewelers.com.

GLOSSARY OF DIAMOND TERMS

BRILLIANCE

The brightness created by the reflection of light that makes a diamond unique. Brilliance iscreated when light enters through the table, travels down to the pavilion and is reflected backthrough the table.

CROWN

The upper portion of the stone above the girdle.

CULET

The lowest point on the bottom of the diamond. It is the smallest facet.

DEPTH

The distance between the table and the culet. It is measured in millimeters. The depth percentage refers to the comparison of the diamond’s depth to its width.

FACET

The smooth flat surface of a diamond that allows light to enter and be reflected.

FEATHERING

Small fractures in a diamond. When examined under a microscope, they resemble a feather.

FIRE

A rainbow of color. When white light hits a skillfully cut diamond, the light is reflected in a prism effect, creating flashes of color. This is also referred to as dispersion.

FLUORESCENCE

A diamond’s distinctive glow when the stone is seen under an ultraviolet light. The fluorescenceof a diamond is defined by its intensity, as either None, Faint, Medium, Strong or Very Strong.

In the very high colors; D, E, and F, strong blue fluorescence is less desirable. However, in the slightly lower colors of J and below, strong blue fluorescence is desirable, as it makes thediamond appear whiter.

GIRDLE

The dividing line between the top and bottom of the stone. It forms the perimeter around thewidest part of the stone and is often the part held by prongs in a setting.

GRAINING

ATiny internal imperfections that may appear milky or as streaks.

INCLUSIONS

Internal imperfections in the diamond that can affect its clarity grade.

PAVILION

The bottom part of the stone from the girdle to the culet.

POLISH

The finishing touch to the facets. The polish is graded from Excellent to Poor. Select a diamond that is graded Good or higher for polish.

SCINTILATION

Sparkling tiny flashes of reflected light.

SYMMETRY

The alignment and positioning of the diamond’s facets. The symmetry of a diamond generally rangesfrom Excellent to Poor. When purchasing a diamond, select one that is defined as Good or higher.

TABLE

The flat top facet in the center of the stone. It is the largest facet of the diamond.

Always consult an expert certified gemologist before investing in a diamond. To speak with an expert call or email (561) 716-0377, Info@MatthewGreenJewelers.com.

DIAMOND SHAPES

Round Cut Diamond

This shape is the most popular and accounts for more than 75 percent of all diamond purchases.

Princess Cut Diamond

This square cut requires a higher depth percentage in order to maximize its brilliance. It has fewer facets than the typical cuts. A princess cut diamond ring is very flattering to a hand with long fingers.

Radiant Cut Diamond

TAnother square cut, this shape combines the squared corners of the emerald cut with the brilliance of the round. With 70 facets, it requires a higher depth percentage in order to maximize its brilliance.

Emerald Cut Diamond

This rectangular shape is a step cut. It has fewer facets than a brilliant cut and is most attractive in simple designs. Inclusions and inferior color may be more pronounced in this cut; higher grades of color and clarity are recommended.

Pear Cut Diamond

TResembling a teardrop, this hybrid cut combines the best of an oval and a marquise. It is one of the most difficult shapes to cut and is often used for pendants and earrings. In a ring, this shape diamond is especially flattering to a hand with small or average-length fingers.

Oval Cut Diamond

Perfectly symmetrical, this elongated shape gives the illusion of length.

Marquise Cut Diamond

Featuring an elongated shape and pointed ends, the marquise can often look larger than other shapes of the same carat weight. According to legend, Louis XV of France commissioned this shape to match the smile of his mistress, the Marquise de Pompadour.

Heart Cut Diamond

With this shape, the diamond has a tiny cleft at its top. Look for a plump stone with a well defined outline and even shoulders.

Triangle Cut Diamond

Having 25 facets on the crown and 19 facets on the pavilion, this shape is often used as a side stone.

Baguette Cut Diamond

Small rectangular stones, baguettes are often used for accents.

Always consult an expert certified gemologist before investing in a diamond. To speak with an expert call or email (561) 716-0377, Info@MatthewGreenJewelers.com.

Selecting a setting is a matter of personal taste.

Before you make your purchase, it is advisable to try on different settings to see which best accentuates the diamond — and is most flattering to you.

Prong Diamond Setting

The diamond is held in place by prongs surrounding the diamond. It is most commonly used in solitaire rings. Typically, a four-prong setting is used. Larger, more expensive stones are often set with six prongs. Prongs can be pointed, rounded, flat or V-shaped.

Channel Diamond Setting

In this type of setting, diamonds of the same size are lined up next to each other and set in a groove between two strips of precious metal. There is no visible metal between the stones and

Bezel Diamond Setting

The diamond in a bezel setting is placed in a continuous groove in the precious metal. The edges of the metal are then closed over the edge of the diamond to hold it into place. Normally, only the upper portion of the diamond — from the girdle up — is visible.

Tension Diamond Setting

In a tension setting, the diamond is held in place by the tension created by the band. This setting requires a sophisticated technique and the use of special alloys to enable the metal to retain its shape.

Pave Diamond Setting

This setting generally uses smaller diamonds that are set as closely together as possible to create a “paved” effect so there appears to be no metal between the diamonds.

Bar Diamond Setting

Similar to a channel setting, here, each stone is held in place by a long thin bar that is placed between the two stones.

Always consult an expert certified gemologist before investing in a diamond. To speak with an expert call or email (561) 716-0377, Info@MatthewGreenJewelers.com.

Asscher Antique Diamond Cut

Developed in the 1920s by Joseph Asscher, a diamond cutter in Holland, this cut features a square-like shape with distinctive corners that give it the appearance of an octagon. It has 72 facets.

Old Mine Antique Diamond Cut

The old mine is an early cut that followed the shape of the rough and was often uneven because of the technology available at the time. The crown is higher and the pavilion is deeper than in modern stones. While the table is very small, the culet is very large and can often be viewed from the top with the naked eye.

Old European Antique Diamond Cut

The Old European is usually round and is the precursor to the modern round brilliant. While the crown is higher than in modern cuts, it is lower than in the old mine. The pavilion is not as deep as in the old mine. It also has a visible culet, but it is smaller than that of the old mine.

Emerald Antique Diamond Cut

This rectangular shape is a step cut. It has fewer facets than a brilliant cut and is most attractive in simple designs. Inclusions and inferior color may be more pronounced in this cut; higher grades of color and clarity are recommended.

Rose Antique Cut

Developed in the sixteenth century, the rose cut was one of the first faceted diamonds. It features a flat base and facets radiating from the center in multiples of six. The rose cut appears in round, pear, oval and triangular shapes.

Cushion Antique Diamond Cut

The cushion cut features rounded corners that soften its square outline. Also called “pillow-cut” or “candlelight” diamonds, these diamonds have larger facets.

Always consult an expert certified gemologist before investing in a diamond. To speak with an expert call or email (561) 716-0377, Info@MatthewGreenJewelers.com.

Branded Diamonds

Some companies have created their own diamond shapes, which they name, trademark and market as their unique brand. Selecting these diamonds is a matter of personal preference. However, you should be aware that these "branded" diamonds may be more expensive when compared with other diamonds of similar color, clarity, carat weight and cut.

Always consult an expert certified gemologist before investing in a diamond. To speak with an expert call or email (561) 716-0377, Info@MatthewGreenJewelers.com.

DIAMOND SETTING - THE METALS

Stones can be set in different metals. Gold, platinum and sterling silver are the most common. However, some designers are using stainless steel, titanium and palladium. The color of the metal is a personal choice, but keep in mind that it can enhance the color of the stone. For example, a very white diamond will appear whiter against a white setting. A diamond with traces of yellow may look more yellow in a white setting or may look whiter set against yellow gold.

Gold

Naturally yellow in color, gold will not tarnish. While it is strong, gold in its purest form is too soft for most jewelry purposes and must be mixed — or alloyed — with other metals to increase its strength and durability. The color of gold is affected by the concentration of alloys such as nickel or copper. A high concentration of nickel or palladium creates white gold, while rose gold gets its color from a high percentage of copper. White gold’s shiny white color occurs when it is plated with rhodium, a metal belonging to the platinum family.

Gold’s purity is measured in karats, which are used to indicate the percentage of gold. Karat — spelled with the letter “k” — always refers to the purity of metals. Note the distinction in the spelling of carat, which indicates the weight of a diamond or other gemstone. Pure, 100 percent gold is 24 karat. It is more expensive, but not as durable, as 18 karat — 75 percent gold — or 14 karat — 58.3 percent gold. When comparing gold jewelry, remember that the higher the number of karats, the greater the gold value.

By law, anything less than 10 karats cannot be sold as gold in the United States. Always look for the karat mark or “k” on the back of the jewelry to determine the gold content.

• 18 karat gold — will be marked 18k or 750(the European designation meaning 75 percent gold)
• 14 karat gold — will be marked 14k or 585
• 10 karat gold — will be marked 10k or 417

Platinum

 Louis XVI of France believed platinum was the only metal fit for a king. Sleek and elegant, platinum’s natural white luster enhances a diamond’s radiance. Thirty times rarer than gold and heavier, platinum is also the strongest of the precious metals used in jewelry. It is tarnish free and hypoallergenic.
Platinum is more valuable than gold. Almost 160 tons of platinum are produced annually in comparison to approximately 1,500 tons of gold. In fact, 10 tons of ore must be mined to produce just 1 ounce of platinum.
Unlike gold, platinum is often 90 to 95 percent pure. It is frequently alloyed with gold, nickel, iridium, palladium, rhodium, or ruthenium. Platinum jewelry that meets the established standards is marked 900Pt, 950 Plat or Plat. In the United States, in order to be marked “Platinum” or “Plat,” jewelry must contain at least 90 percent platinum.
Always look for the marking to ensure that the material is platinum and not white gold or another metal.

Palladium

Palladium is a metal from the platinum family.

Sterling Silver

Derived from the Latin for “white and shining,” silver entices with its sophisticated sheen. Like gold, it is too soft in its purest form to be used to make jewelry. Copper is the most frequently used alloy because it is very effective in adding durability to silver.
Sterling silver is a mixture of 92.5 percent pure silver and 7.5 percent copper. Silver is not designated with a karat weight; sterling silver is considered 92.5 percent pure and is stamped with the mark 925.

Titanium

Titanium is a lustrous metal that resists corrosion.

Always consult an expert certified gemologist before investing in a diamond. To speak with an expert call or email (561) 716-0377, Info@MatthewGreenJewelers.com.com.

COLORED DIAMONDS

Rare and very expensive, natural colored or “fancy” colored diamonds reflect the colors of the rainbow.

Yellow is the most common colored diamond, while pink, red, blue and green diamonds are extremely rare. Fancy color diamonds are cut to maximize color, not clarity. Of the 4Cs, color is the most important criterion for these stones. Generally, the higher the saturation of color, the more valuable the stone.

The appearance of color is created from the combined effect of

• hue – the predominant color
• tone – the darkness of the color
• saturation – the intensity of the color Diamonds get their color from trace elements or internal structural anomalies in the diamond. For example, Brown is caused by a distortion of the atomic structure of the stone. Brown diamonds vary in shades from Champagne to Cognac.

Yellow gets its color from the presence of nitrogen

• Blue diamonds are created from trace elements of boron.
• Pink diamonds owe their coloring to a phenomenon in the crystal lattice structure of the diamond.
• Green diamonds were exposed to natural radiation as they were forming billions of years ago.

The GIA uses specific grades to identify the ranges of color

• Faint
• Very Light
• Light
• Fancy Light
• Fancy
• Fancy Intense
• Fancy Vivid
• Fancy Dark
• Fancy Deep

Always consult an expert certified gemologist before investing in a diamond. To speak with an expert call or email (561) 716-0377, Info@MatthewGreenJewelers.com.

WHAT ARE THE DIFFERENT TYPES OF DIAMOND TREATMENTS?

There are Various ways of “treating” a diamond, such as heat. Heat can be used to enhance the colorlessness of a diamond or intensify the color of fancy colored diamonds. The results of these treatments can produce temporary or permanent results. However, treated stones are worth far less per carat than natural stones.

These are the other common diamond treatments in use today:

HPHT

High Pressure-High Temperature (HPHT) is a process that applies extreme pressure —approximately 850,000 pounds per square inch — and very high temperature — of about 1,600 degrees centigrade — to the diamond. By altering the molecular structure of natural diamonds, HPHT greatly enhances their color. Only certain types of diamonds can be affected by this treatment, which can turn a brown diamond colorless.

Chemical Vapor Deposition

This square cut requires a higher depth percentage in order to maximize its brilliance. It has fewer facets than the typical cuts.

Laser Drilling

Lasers are used to minimize the appearance of flaws and make them less visible. The results of laser drilling are permanent. Drilling will and does leave colorless cavities in the diamond.

Irradiation

The irradiation of diamonds can result in the production of fancy colored stones, especially blues, greens and deep yellow. Radiation may also be used to reduce the flaws on a diamond.

Painting

This process involves painting a very thin coat of a chemical substance over the entire stone, or part of it, to improve the color. Painting neutralizes the yellow in the stone and can improve the color by as much as seven grades.

Always consult an expert certified gemologist before investing in a diamond. To speak with an expert call or email (561) 716-0377, Info@MatthewGreenJewelers.com.

SYNTHETIC DIAMONDS

Synthetic diamonds are “grown” in a laboratory using sophisticated techniques such as HPHT and CVD. While synthetic diamonds exhibit the same chemical and physical properties as a natural diamond, they cannot completely replicate natural diamonds.

One of the most popular simulated stones is cubic zirconia (CZ), a mineral that when synthesized simulates a diamond.

HPHT (High-Pressure High-Temperature) mimics the geological conditions that create natural diamonds. This method of applying high pressure and high temperature to a carbon diamond “seed” can produce a synthetic diamond in approximately three and one-half days. In the CVD process (Chemical Vapor Deposition), moderate heat is applied to hydrogen and methane in a vacuum chamber, producing a chemical reaction that creates a diamond seed.

Always consult an expert certified gemologist before investing in a diamond. To speak with an expert call or email (561) 716-0377, Info@MatthewGreenJewelers.com.