Diamond, Gemstone and Pearl Buying Guide
Characteristics and Types of Pearls, Gemstones and Diamonds
The American Gem Trade Association has published a public guide which clearly defines the types, clarity, cut and carat weight of gemstones, diamonds and pearls. This allows customers to fully understand what they’re buying and all the available options. If you have any questions about anything in the guide, don’t hesitate to contact The Jewelry Center. We’re always happy to help you find the perfect piece.
Contact the Greenfield jewelers for more information about gemstones, diamonds or pearls today.
GEMSTONE ENHANCEMENT CODES
Published by the American Gem Trade Association.
|Pearl Facts||Ring Sizing||The 4 C's Of Diamonds|
|The 4 C's Of Gemstones||Diamond & Gemstone Size Ranges||Metal Types|
Because of the rarity of naturally occurring pearls, a process of cultivating pearls was introduced in the early 1900s. In this process, a small bead of polished shell is inserted into an oyster or mollusk to act as an irritant and produce a pearl, which can take up to 24 months. These pearls are referred to as cultured pearls. Pearls are classically elegant and never go out of style.
Types of Pearls
Akoya-These pearls were the first type of pearl to be cultured. Japan and China are the main producers of these pearls. They are consistently round, which makes them perfect for strands. Colors range from white to cream, though some can be gray or black.
Freshwater-The freshwater pearl is usually slightly less round, smaller in size, and possesses less luster than other varieties of saltwater pearls. These pearls are usually cultivated in China and provide a value-priced option
Mabé-(MAH bay) Instead of growing inside an oyster or mollusk like other pearls, the mabé pearl actually grows against the shell of the oyster, creating a dome-shaped pearl. This pearl is harvested, then assembled. The nucleus is removed and replaced by resin, while mother-of-pearl is used to cover the flat back. Mabés traditionally have high luster and lower prices than round pearls.
South Sea-These pearls are cultured in the northern waters of Australia, Indonesia, and the Philippines. These pearls are considerably larger than akoya pearls and much more sensitive during the cultivation process. South Sea pearls are naturally white, cream, or golden in color.
Tahitian-These pearls are slightly smaller than the South Sea pearl, but are also sensitive during the cultivation process. The colors of black, silver, and gray occur naturally and they are cultured in Tahiti as their name implies.
Pearls are produced in a variety of colors, as noted in the types of pearls. Most range from white, cream, and yellow to pink, silver, and black. Most pearls will have both a primary color, the first color you will notice, and a secondary color, the overtone you notice when you take a closer look. Color variation does not decrease the value of the pearl, but is important when matching pearls to be used in strands, earrings, bracelets, etc.
A pearl's luster is the result of multiple layers, also called the nacre (NAY ker), that the oyster or mollusk secreted to make the pearl. The thicker the nacre, the more luster a pearl has. You will notice the luster as the deep sheen that reflects light on the surface of the pearl.
Pearls come in a variety of different shapes. The most coveted of these is round. Akoya, Tahitian, and South Sea pearls are most often the roundest of the pearls. Other shapes can make beautiful jewelry as well, sometimes providing you with different price options.
Because pearls rely on an uncontrollable environment in which to grow, very rarely will you find a perfect pearl. The surface of a pearl may not always be smooth, often including spots, bumps, etc. The beauty of these pearls may be enhanced by the ability to sometimes be camouflaged during the stringing and setting process.
The size of the oyster or mollusk that a pearl is produced within will have a direct effect on the size of the pearl. The size alone may not greatly impact the price of a pearl, but when you combine it with a perfectly round shape and beautiful luster, the value will dramatically increase.
We offer custom ring sizing at no additional charge. Most of our rings can be sized, but due to the nature of some designs, not all rings can be sized. When placing your order, an asterisk (*) beside a ring size option lets you know that your ring will be custom sized. Size options without the asterisk are stock sizes. Most custom sized ring orders leave our facility in as little as two business days. Use our convenient Ring Sizer to determine your ring size. Custom sized rings are not accepted for return.
THE 4 C's OF DIAMONDS
Buying a diamond is often a very personal experience. Diamonds can be bought to signify love, significant accomplishments, or milestones in your life or that of a gift's recipient. Unlike when you buy clothing, electronics, or cars, the features of a diamond may not seem quite so obvious to you. At ShopTJC.com, we would like to change that. The more you know about your diamond jewelry, the more confident you will feel when making your diamond jewelry choices. Take a moment to learn more about the 4Cs and find out how they play an important role in making your diamond jewelry unique.
The shape of the diamond is often confused with the cut. ShopTJC.com carries diamonds that are round, princess, oval, pear, and marquise. Choose the shape that you like based on your style and you cannot go wrong. (See Figure below)
The cut of a diamond determines its brilliance or sparkle. Each shape will be cut differently. Before a diamond is cut, the location of inclusions and flaws, the natural coloration, and the original shape of the rough stone are studied extensively. The stone facets are then mapped out and cut in a way that maximizes size, shape, and clarity. For optimal light performance, you will want a diamond that is cut neither too shallow nor too deep, like the stones that ShopTJC.com offers. (See Figure below)
Diamonds are graded based on the amount of color they do or do not possess. The scale runs from D (colorless) to Z (light yellow). An absolutely colorless diamond is rare and therefore very valuable. At ShopTJC.com, our jewelry contains near colorless (G-J) diamonds because we feel that they give you the best overall value. (See Figure below)
A diamond is distinguished by its natural characteristics, just as a person would be noted for her blue eyes or his brown hair. Notated as a diamond's clarity, these characteristics can be present on the surface (blemishes) or within the stone (inclusions). The clarity is judged by the number and types of these characteristics and is designated using a scale that runs from Fl, defined as flawless, to I3, defined as inclusions visible with the naked eye. A flawless diamond is truly rare. (See Figure below)
The unit of measure used for the weight of a diamond is the carat. As a matter of reference, a carat is equivalent to .2 grams or .007 of an ounce. Carat weight can also be divided further by using points. There are 100 points in one carat. So a 1/4 (.25) carat stone can also be expressed as 25 points and mean exactly the same thing. When comparing two diamonds, please note that just because one is twice the carat weight of the other does not mean that it will appear to be twice the size.
THE 4 C's OF GEMSTONES
Buying a gemstone is often a very different experience than buying a diamond. Gemstones are bought based on favorite colors, wardrobe matches, personality, and fashion trends. While gemstones are judged using the 4Cs, just as diamonds do, each is judged separately. For example, a sapphire is compared to another sapphire, but wouldn't be compared to an emerald or aquamarine. Choose your gemstone jewelry based on your personal preferences.
ShopTJC.com sells a number of different shaped gemstone jewelry. Some of our most popular shapes include round, marquise, oval, pear, princess, and baguette.
Gems are cut in a variety of different ways. Transparent stones will often be cut with facets. Unlike diamonds, the facets are planned to maximize the color. Other stones like jade, opal, and onyx will be cut into a smooth domed shape known as a cabochon. While still other stones like cameos are intricately carved.
Gemstone color is different from judging the color of a diamond. Every gemstone has a range of color that runs from light to dark and more vivid to less vivid, with a small range of color considered preferable. All of the families of color are represented by gems of different types
Ruby, Garnet, Red Spinel, Alexandrite, Pyrope, Tourmaline, Beryl
Rhodolite, Pink Garnet, Pink Sapphire
Akoya Pearl, Freshwater Pearl, Mabe Pearl, South Sea Pearl, White Spinel, White Topaz, Moissanite, Opal
Yellow Sapphire, Citrine
Tahitian Pearl, Onyx
Aquamarine, Blue Chalcedony, Blue Spinel, Blue Zircon, Lapis, Sapphire
Gems also have internal characteristics called inclusions. Some gemstones are known for having many inclusions like emerald or for having few inclusions like citrine. Each gemstone will be graded for clarity differently.
Like diamonds, gemstones are measured using carats. A carat is equivalent to .2 grams or .007 of an ounce. Unlike diamonds, each gemstone has a different density which greatly contributes to the weight of the stone.
DIAMOND & GEMSTONE SIZE RANGES
We take pride in offering great value and quality. In order for us to offer this value, it is necessary to buy and sell diamonds in weight ranges. To help assist you in understanding these ranges, we have provided the following chart of size tolerances.
|Accent .004 min.||3/4 .66 min.||2 1/3 2.29 min.||4 1/8 4.10 min.||5 3/4 5.66 min.|
|0.01 .008 min.||7/8 .84 min.||2 3/8 2.37 min.||4 1/6 4.14 min.||5 7/8 5.84 min.|
|0.015 .012 min.||9/10 .90 min.||2 1/2 2.45 min.||4 1/5 4.18 min.||5 9/10 5.90 min.|
|0.02 .015 min.||1 .96 min.||2 5/8 2.60 min.||4 1/4 4.23 min.||6 5.96 min.|
|0.025 .02 min.||1 1/8 1.10 min.||2 3/4 2.66 min.||4 1/3 4.29 min.||6 1/8 6.10 min.|
|0.03 .025 min.||1 1/6 1.14 min.||2 7/8 2.84 min.||4 3/8 4.37 min.||6 1/6 6.14 min.|
|0.04 .035 min.||1 1/5 1.18 min.||2 9/10 2.90 min.||4 1/2 4.45 min.||6 1/5 6.18 min.|
|0.05 .045 min.||1 1/4 1.23 min.||3 2.96 min.||4 5/8 4.60 min.||6 1/4 6.23 min.|
|0.06 .055 min.||1 1/3 1.29 min.||3 1/8 3.10 min.||4 3/4 4.66 min.||6 1/3 6.29 min.|
|0.07 .065 min.||1 3/8 1.37 min.||3 1/6 3.14 min.||4 7/8 4.84 min.||6 3/8 6.37 min.|
|0.08 .075 min.||1 1/2 1.45 min.||3 1/5 3.18 min.||4 9/10 4.90 min.||6 1/2 6.45 min.|
|1/10 0.09 min.||1 5/8 1.60 min.||3 1/4 3.23 min.||5 4.96 min.||6 5/8 6.60 min.|
|1/8 .11 min.||1 3/4 1.66 min.||3 1/3 3.29 min.||5 1/8 5.10 min.||6 3/4 6.66 min.|
|1/6 .14 min.||1 7/8 1.84 min.||3 3/8 3.37 min.||5 1/6 5.14 min.||6 7/8 6.84 min.|
|1/5 .18 min.||1 9/10 1.90 min.||3 1/2 3.45 min.||5 1/5 5.18 min.||6 9/10 6.90 min.|
|1/4 .23 min.||2 1.96 min.||3 5/8 3.60 min.||5 1/4 5.23 min.||7 6.96 min.|
|1/3 .29 min.||2 1/8 2.10 min.||3 3/4 3.66 min.||5 1/3 5.29 min.|
|3/8 .37 min.||2 1/6 2.14 min.||3 7/8 3.84 min.||5 3/8 5.37 min.|
|1/2 .45 min.||2 1/5 2.18 min.||3 9/10 3.90 min.||5 1/2 5.45 min.|
|5/8 .60 min.||2 1/4 2.23 min.||4 3.96 min.||5 5/8 5.60 min.|
There are a variety of metals choices available for jewelry. Whether you like the allure of platinum or the range of options with the classic gold, you will find a number of stylish pieces, sometimes even combining the two metals. Today, alternative metals like sterling silver, titanium, and stainless steel give you additional options in look, strength, price, etc. Each choice has its own qualities, so base your choice on the ones that you value most.
Platinum is generally 95% pure and does not tarnish or lose its rich white luster. Platinum is the heaviest of all the precious metals weighing approximately twice as much as karat gold. Its purity makes it hypoallergenic, perfect for people who are sensitive to the alloys used in gold. Platinum is also known for its strength and pliability, just one gram of platinum can drawn into a fine wire over one mile long.
Pure 24 karat gold is rarely used in jewelry because it is too soft for frequent wear. Gold is mixed with alloys like copper, silver, nickel, and zinc to give different colors, strength, and durability. Gold's purity is measured in karats, which indicate out of 24 parts how many parts are gold. For example, 18kt gold contains 18/24 gold and 6/24 alloy, while 14kt gold contains 14/24 gold and 10/24 alloy. Gold is traditionally seen in yellow and white colors, but can also be available in rose or green on occasion.
Sterling silver is usually 92.5% silver and 7.5% copper. Silver is much more plentiful than platinum or gold and is much less expensive. It takes on a much higher polish than any other metal, but it does tarnish. The tarnish can be removed, but silver requires much more care than other metals.
Titanium is a light, strong, and corrosion-resistant metal. Titanium offers you seven times the strength of platinum at about 1/3 of the weight. It is the hardest natural metal on earth and therefore offers more scratch resistance than gold or silver. In addition, titanium is also hypoallergenic. When ordering titanium rings, be extra sure about your ring size. The biggest drawback of titanium rings is that they cannot be sized by traditional ring sizing methods.
Stainless steel is a low cost alternative to traditional metals. It is naturally hypoallergenic and will not rust or tarnish. Stainless Steel will not break or bend under normal usage and is stronger than any other alloy.