The Girlfriend's Guide to Jewellery

by Anne Wallner Rss
21: Cut

Whatever the clarity or colour of a diamond it is the cut that brings a diamond to life! Most people don't need a microscope to appreciate the brilliance of a diamond or to notice its lack of brilliance. Either way, it is the cut that can give a diamond the fire and sparkle we all love. The temptation to retain greater finished weight from the rough crystal can cause a cutter to deviate from the ideal proportions when cutting a diamond thus diminishing the fire and brilliance of the finished stone. The cut grade of a diamond has three components: proportions, symmetry and finish. An ideal grade in all three categories is the finest possible of cut grades. It is a grade very rarely achieved and requiring a great deal of time and the skill on part of a master cutter. What we know today as the round brilliant cut has been developed over centuries in an ongoing search for the form to release the maximum brilliance and dispersion from rough diamond material. The round shape brings...

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20: The Language of Diamond Grading

Diamonds are described in terms of what we refer to as the 4 C’s: cut, colour, clarity and carats weight. These days, now that Canada is the world’ s third largest producer of diamonds, by weight, some us want to say we need 'Five C’s': cut, colour, clarity, carat weight and of course, Canadian! For now we’ll settle on those original four C’s as they are listed on grading charts. We will look at them in their order of impact on a diamond’s beauty and the language used to describe and quantify them. There are two primary diamond-grading systems used and recognized around the world. One system has been developed by the American Gem Society (A.G.S.) and the other by the Gemmological Institute of America (G.I.A.). Each of these grading systems assigns a cut, colour and clarity grade to a diamond and verifies the weight of the loose stone. It should be noted that grading reports or ‘certs’ as they are known do not assign dollar values to stones; they are grading reports...

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19: Calibrated Gemstones

In the trade we refer to gemstones that are cut to conventional shapes and sizes as 'calibrated stones'. Calibrated gemstones are cut in a range of consistent proportions and dimensions calculated to fit into a host of independently designed and manufactured mounts which have in turn been designed and manufactured to match the size and shapes of a range of calibrated gemstones. Imagine if each gemstone were cut into an individual shape and size; every stone would require a dedicated hand made setting! Matching the size and shape of the gemstones to the mounts is an enormous cost saver. You can see that cutting the gemstones and designing the settings to accommodate them in a vast selection of ring, pendant, earring, bracelet or brooch styles and then casting these designs in various metals makes the possible combinations almost endless and at the same time reduces costs significantly. Rare, expensive and rough gem material of exceptional quality is still often cut by hand. The gem...

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18: Cabochon

When a stone has an overall polished dome shape we call it a cabochon cut. A cabochon may be any of the shapes we have mentioned as well as a myriad of fancy or free form shapes. All cabochons have a smooth polished domed topside and either a flat or slightly domed underside. The underside is usually but not always polished. A well cut cabochon has smooth all over even polish with no flat surfaces on the polished dome of the stone. The outer edge of a cabochon is called the girdle of the stone. It defines the outline of the stone's shape. An irregular girdle will give a stone an irregular and uneven shape. It is around or on the girdle that the setting will rest to secure the stone in the mount. A cabochon cut is usually reserved for opaque or translucent gem material but transparent material can also be very beautiful when cut 'en cabochon'. Freeform Freeform stones are often whimsical expressions of the cutters' art. They can be beautiful, precious small-scale...

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17: Faceting

Typically, transparent gem quality material is polished and facetted. Faceting should leave the stone symmetrical, evenly proportioned and with good polish or finish. Revealing the beauty of the gem material is the goal of the cutter, that and maintaining maximum weight from the original rough material. Some material is still cut by hand. Exceptional gem material is cut by a master-hand. There are various patterns of faceting and most facetted gemstones have a crown, a girdle and a pavilion. The 'girdle' separates the 'crown' from the 'pavilion' and can have the appearance of a fine to thick 'whitish' line. Often the 'girdle' is left unpolished though it is becoming a style to facet the girdle of diamonds. While the girdle is the smallest part of a facetted gem it plays two important roles. One, it defines the outline of the stone's shape: an irregular girdle will give a stone an irregular and uneven shape; and two, it is around or on the girdle that the setting will rest to...

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16: Cutting

Size The size of a gemstone is described by its measurements. Gemstones are usually measured in millimetres or fractions of millimetres in three directions: width, length and depth. For most of us choosing a gemstone is a visual choice. While we are probably not familiar with the actual carat weight of a sapphire or an amethyst we know what size we like when we see it. The one exception to this approach might be diamonds. Most of us have looked at diamonds and they are almost always shown to us along with a comment regarding their weight, 'this stone is a half carat' or 'this diamond weighs a full carat'. As a result, it is not uncommon to hear someone express the size of diamond they want in terms of its carat weight, 'I want a one carat diamond'. Shape The shape of a gemstone is its form or the outline it presents. The shapes we encounter most often include round, oval, pear, cushion, heart, square, emerald, rectangle, triangle, marquise and free form. Some less frequently...

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15: Density

When we were kids our dad used to tease us asking 'what is heavier, a pound of lead or a pound of feathers?' of course the answer is that they both weigh the same. What is different is their relative size or volume. A pound of lead is pretty small and a pound of feathers is huge! This is a lesson in a contrast between two materials each of vastly different density. Different gemstones have different densities. Density is referred to or measured as the 'specific gravity' of a material. The 'standard' for measuring density is the weight of one cubic centimetre or 1cc of water. At sea level and at 4 degrees celcius one cubic centimetre of water weighs one gram. Water is our 'benchmark' and it has a specific gravity of 1. A volume equal to 1cc of diamond is 3.45 times as heavy as 1cc of water. Diamond has a specific gravity of 3.45. Sapphire is 5.43 times as heavy as water and has a specific gravity of 5.43. What we see is that sapphires are actually heavier than diamonds, 1.57 times...

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14: Durability

Durability is an important and practical characteristic of gemstones. Durability refers to several of a gem's characteristics such as how easily it can fracture, or how easily it scratches or chips. As beautiful as a stone may be if it not durable it will not be suitable for wear as jewellelry and it is not included on our list as a 'gemstone'. Stones that lack durability and are not considered 'gemstones' may be very beautiful and have considerable value as collectible polished or facetted stones and as mineral specimens. Each gemstone is assigned a hardness rating according to the Moh's Scale. Moh's Scale: The Moh's hardness scale is a scale of relative hardness running from the softest at 1 to the hardest at 10. It is a scratch test where the softest is talc at 1 and the hardest is diamond at 10. According to the Moh's scale each successive stone on the scale can scratch all of those below it. This scratch test is a test of hardness not indestructibility. Clearly...

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13: Carat

Carat describes weight the same way that pound and kilogram do. A carat is a much smaller measure of weight. One carat is equal to 1/5 of a gram. It takes five carats to equal one gram; 5.00cts equal 1 gram. All gemstones are sold by weight, that is, by the carat. We can think of a carat in the same way as we do a dollar. One dollar is written $ 1.00; one carat is written 1.00ct. A dollar is made up of 100 'cents'; a carat is made up of 100 'points'. 1/100 of a dollar is one cent, and is written $0.01. 1/100 of a carat is one point, and is written 0.01ct. We use the word 'points' for any size smaller than one carat, that is to say, for weights up to 0.99ct or ninety-nine points. With dollars the single zero before the decimal point is often omitted. With carats it is always included: 0.10ct is 'ten points'; 0.79ct is 'seventy-nine points' and 0.015ct, is 'one and a half points'. For a carat or more we say it the way we write it: 1.32ct is 'one carat thirty-two' or ' one...

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12: Style

A parallel may be drawn between the jewellery world and the clothing world. A custom designed and hand made 'one of a kind' piece of jewellery is as special, individual and rare as a couturier runway creation. 'Limited edition' pieces, the designer name brand lines that are sold through exclusive contract at jewellery stores around the world, are roughly the equivalent to the upscale name brand clothes sold in boutiques and chic 'Downtown' department stores. Both deliver the pride, confidence and the prestige of wearing a recognized and elite 'peer approved' designer name. We recognize that these pieces, be they jewellery or clothes, are of consistent and dependable quality. Based on the styles and trends established by these famous designers come a myriad of distant cousins: the 'wannabes' and knockoffs. From the consumer perspective, the further 'down the chain' a piece is from the original designer house, the more relaxed our expectations become. Though the look may be...

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