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THE QUALITY OF MELEE DIAMONDS
Regardless of a diamond’s size, the beauty of its brilliance is determined by the quality of the rough material from which it is polished. Diamond rough is produced by nature under the extreme temperatures and pressures that are present deep below the earth’s surface. These raw diamonds vary widely in shape, and none of them are absolutely perfect. Rough diamonds that are eventually used in jewelry can be broadly classified into three groups-sawable, makable, and cuttable (or near-gem). The shape and quality of the rough material determines the type of cut a diamond will receive, and also has a critical effect on the beauty of its finish. |
A beautiful diamond is highly transparent and shines brilliantly. It shows a rainbow of dispersion when bright light is shined on it. A beautiful diamond sparkles with scintillation as it is moved, and has a fine overall appearance. The gem-quality diamonds below to the left exhibit beautiful brilliance, but the accessory-quality stones to the far right have a poor transparency that diminishes their beauty. Besides beauty, an important criterion of gem-quality diamonds is that they do not contain any imperfections that are discomforting or that have a negative effect on durability. |
Gem-quality diamonds are valuable because they are far rarer than other diamonds, according for only 10 to 15 percent of all diamonds, and because most people simply prefer them. Comparing the relative values of two- to three-millimeter-size diamonds, and assigning a value of jewelry-quality diamonds would be 5 and accessory quality would be 1. |
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| Sawable |
| This rough material most often appears in an octahedral shape, which resembles two pyramids joined together at the base. This rough, which is crystallized in a fairly orderly fashion, is characterized by its high transparency. Only 10 to 15 percent of all diamonds used as gemstones, including near-gem, fall into this category, and it is a valuable material that can be cut efficiently. |
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| Gem Quality |
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| Makable |
Makable rough varies widely in shape, and represents the medium-quality level of diamond rough. Each piece of rough is fashioned according to its shape. While even those with poor shape may end up as high-quality polished diamonds, some will only become low-quality diamonds that are lacking in beauty.
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| Jewelry Quality |
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| Near-Gem |
Barely usable as a gem material, this type of rough was originally considered to be of industrial quality. Lacking in transparency, most of these stones contain large black inclusions or numerous fractures. Even after polishing, their transparency is low, and they exhibit almost no beautiful brilliance. Near-gem diamonds are used in low-cost jewelry.
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| Accessory Quality |
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