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Colored Diamonds: Diamonds which are pronounced in color are not graded by the above standards--often their value is considerably higher because of their color, which is not only found in shades of yellow and brown, but also in blues and greens. One of the most famous examples of a high-value colored diamond is the spectacular blue Hope Diamond. The informally-termed "Champagne" color group is used to designate light-brown-tinted diamonds, popular in larger sizes in yellow gold settings, and in smaller sizes where color is less noticeable. The lightest-color versions of this color group are often called TTLB, or Top Light Brown. Yellow diamonds are also popular, as in our Yellow and White Diamond Heart Ring. To learn more about colored diamonds, consult the Natural Color Diamond Association website.
Diamond/Gemstone Weight (wt.), Total Weight (t.w.) in Carats (ct.) / Stone Count: The weight of a gemstone is measured in carats--since 1913 a carat has been defined to equal 200 milligrams. Sometimes fractional carats are designated as points, where 1ct. is 100 points; i.e., a 1/10-carat diamond may be designated as a "10-point diamond". Note that the carat is a measure of weight, not size. A one-carat diamond, because it is more dense, will be smaller than a one-carat emerald. But, the one-carat diamond will be larger than a one-carat ruby, since ruby is more dense than diamond.
In a piece with more than one gemstone, the total weight of the stones, in carats, is referenced as t.w. For a pair of earrings, the t.w is the sum of the weight of stones in both earrings combined. All gemstone weights are referred to as "approximate", and really represent a range of actual weight due to the slight variability of the cutting process and the mixing of multiple stones. At ViridianGold.com, we always specify the minimum actual weight--for instance, a 1/4 carat total-weight diamond ring will be specified as "0.23 ct. t.w.", even though its actual total diamond weight could be as high as 0.28 carats. The table below shows the standard ranges for a few common weights of diamonds:
|Total weight||Weight range|
|1/4 ct.||.23-.28 ct.|
|1/3 ct.||.29-.36 ct.|
|1/2 ct.||.45-.59 ct.|
|3/4 ct.||.66-.83 ct.|
|1 ct.||.96-1.09 ct.|
It is also worth noting that per-carat pricing depends on the size range of the stones. Larger stones command more value per carat than smaller stones--thus a one-carat diamond ring that is made up of five 0.2ct. diamonds will be priced lower than a ring with a single 1-carat diamond, given similar quality diamonds and metal quality.
Small round diamonds are used in large quantities in the jewelry industry--they have acquired their own names for their size groupings: 0.01 - 0.02 cts. (1 and 2 points) are referred to as stars, 0.03 - 0.07 cts. (3 to 7 points) as full-cuts and 0.08 - 0.13 cts. (8 to 13 points) as melées. For the meaning of full-cut when referring to the facet design of a diamond, see definition below.
Diamond Size/Width: Since the carat is a measure of weight, dimensions of a given carat weight diamond will vary greatly depending on its shape and the cut of the shape. In order to provide you with some measure of the size of a stone and its setting, many of Viridian Gold's single-diamond product pages contain a table entry specifying the width in millimeters of the diamond. For a round diamond, we give its approximate diameter, and for a princess cut diamond, we give the approximate height and width dimensions.
Diamond Cut and Polish: The cut of a diamond, or other gemstone, refers not to its shape, but to the quality of the shape. The cut is critical in the resulting sparkle, or scintillation, of the diamond. This is due to the way in which the stone reflects light back to the eye. A poorly cut stone will absorb light that enters it, or else "leak" light out the sides and bottom of the stone, rather than directing it back out of the top (the table) of the stone. The quality of the cut is determined by the mathematical ratios of the angles of the facets of the stone in relation to each other, as well as the height/width ratio of the stone and the thickness of the girdle (the widest part of the stone). Proper cut can be compromised to yield a stone with a greater weight--hence the unfortunate tendency to sacrifice the brilliance of a stone in order to create a heavier, and thus possibly more valuable, diamond. In recent years, however, the cut quality of diamonds has received much more consideration in determining value--therefore, this has limited the tendency for cutters to sacrifice brilliance for weight. The polish of the stone refers to the smoothness of the facets. Marks from the cutting process can leave striations or ridges on the facets of the diamond which are visible under 10X magnification and which negatively affect its brilliance. The cut and polish are rated for diamonds by the GIA on a 5 point scale progressing from Excellent to Very Good, Good, Fair or Poor. Cut may also refer to the number of facets:
Single Cut, a simple cut (and thus less expensive) with only 17 facets (9 on crown and 8 on pavilion). This is commonly seen on small stones (1-13 points).
Full Cut is also known as Round Brilliant, and is composed of the standard 58 facets (33 on the crown and 25 on pavilion). Shapes other than round may also have 58 facets, and other proprietary, branded cuts are possible which utilize many more than 58 facets. Thanks to mechanization, even smaller stones are now produced in full cut rather than single cut. Most of our Diamond Jewelry items are set with full-cut, round diamonds--you will always find this information in the table of specifications under the ring's description.
Radiant Cut: A combination of two different cuts, the Radiant combines the Round Brilliant and the Emerald cuts, resulting in an emerald-cut shape that has the sparkle of a round, brilliant-cut diamond.Cushion Cut: Mixed-cut shape with rounded edges. The cut is usually brilliant to give the highest light refraction. OR - A type of brilliant cut in which the girdle has the form of a square with rounded edges.
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