KMG GOLD Gold Buyers Diamonds FAQ

The most familiar use of diamonds today is as gemstones used for adornment, a use which dates back into antiquity.

A diamond is a transparent crystal of tetrahedrally bonded carbon atoms

Gold is a highly sought-after precious metal which, for many centuries, has been used as money, a store of value and in jewelry. The metal occurs as nuggets or grains in rocks, underground "veins" and in alluvial deposits. It is one of the coinage metals. Gold is dense, soft, shiny and the most malleable and ductile of the known metals. Pure gold has a bright yellow color traditionally considered attractive.Excellent optical and mechanical properties, combined with efficient marketing, make diamond the most popular gemstone.

The dispersion of white light into spectral colors is the primary gemological characteristic of gem diamonds. In the 20th century, experts in gemology have developed methods of grading diamonds and other gemstones based on the characteristics most important to their value as a gem. Four characteristics, known informally as the four C's, are now commonly used as the basic descriptors of diamonds: these are carat, cut, color, and clarity. A large, flawless diamond is known as a paragon.

Diamond is the hardest natural material known, where hardness is defined as resistance to scratching and is graded between 1 (softest) and 10 (hardest) using the Mohs scale of mineral hardness. Diamond has a hardness of 10 (hardest) on this scale.

The hardness of diamond contributes to its suitability as a gemstone. Because it can only be scratched by other diamonds, it maintains its polish extremely well. Unlike many other gems, it is well-suited to daily wear because of its resistance to scratching-perhaps contributing to its popularity as the preferred gem in engagement or wedding rings, which are often worn every day.

Diamond has the highest hardness and thermal conductivity of any bulk material. Those properties determine the major industrial application of diamond in cutting and polishing tools.

In order of rarity, colorless diamond, by far the most common, is followed by yellow and brown, by far the most common colors, then by blue, green, black, translucent white, pink, violet, orange, purple, and the rarest, red.

"Black", or Carbonado, diamonds are not truly black, but rather contain numerous dark inclusions that give the gems their dark appearance. Colored diamonds contain impurities or structural defects that cause the coloration, while pure or nearly pure diamonds are transparent and colorless. Most diamond impurities replace a carbon atom in the crystal lattice, known as a carbon flaw. The most common impurity, nitrogen, causes a slight to intense yellow coloration depending upon the type and concentration of nitrogen present. The Gemological Institute of America (GIA) classifies low saturation yellow and brown diamonds as diamonds in the normal color range, and applies a grading scale from "D" (colorless) to "Z" (light yellow). Diamonds of a different color, such as blue, are called fancy colored diamonds, and fall under a different grading scale.

Diamonds can be identified by their high thermal conductivity. Their high refractive index is also indicative, but other materials have similar refractivity. Diamonds cut glass, but this does not positively identify a diamond because other materials, such as quartz, also lie above glass on the Mohs scale and can also cut it.

A large trade in gem-grade diamonds exists. Unlike other commodities, such as most precious metals, there is a substantial mark-up in the retail sale of gem diamonds.

Source: Diamond. (2010, September 28). In Wikipedia, The Free Encyclopedia. Retrieved 08:47, September 28, 2010 from http://en.wikipedia.org/wiki/Diamond

Diamond clarity is a quality of diamonds relating to the existence and visual appearance of internal characteristics of a diamond called inclusions, and surface defects called blemishes. Clarity is one of the four C's of diamond grading, the others being carat, color, and cut.

Inclusions may be crystals of a foreign material or another diamond crystal, or structural imperfections such as tiny cracks that can appear whitish or cloudy. The number, size, color, relative location, orientation, and visibility of inclusions can all affect the relative clarity of a diamond. A clarity grade is assigned based on the overall appearance of the stone under 10x magnification.

The GIA diamond grading scale is divided into six categories and eleven grades. The clarity categories and grades are:

• Flawless (FL) diamonds have no inclusions or blemishes visible under 10x magnification.
• Internally Flawless (IF) diamonds have no inclusions visible under 10x magnification, only small blemishes on the diamond surface.
• Very Very Slightly Included (VVS) diamonds have minute inclusions that are difficult for a skilled grader to see under 10x magnification. The VVS category is divided into two grades; VVS1 denotes a higher clarity grade than VVS2.
• Very Slightly Included category (VS) diamonds have minor inclusions that are difficult to somewhat easy for a trained grader to see when viewed under 10x magnification. The VS category is divided into two grades; VS1 denotes a higher clarity grade than VS2.
• Slightly Included (SI) diamonds have noticeable inclusions that are easy to very easy for a trained grader to see when viewed under 10x magnification. The SI category is divided into two grades; SI1 denotes a higher clarity grade than SI2. These may or may not be noticeable to the naked eye.
• Included (I) diamonds have obvious inclusions that are clearly visible under 10x magnification. Included diamonds have inclusions that are usually visible without magnification. The I category is divided into three grades; I1 denotes a higher clarity grade than I2, which in turn is higher than I3. Inclusions in I1 diamonds often are seen to the unaided eye. I2 inclusions are easily seen, while I3 diamonds have large and extremely easy to see inclusions.
• Most I3 diamonds are not suitable in jewellery and are more suited to being used in industrial applications - such as drill bits. However, relatively inexpensive I3 diamonds are used extensively in jewelry, such as engagement rings of very poor quality

Diamond testing and Diamond value

1. Carat is a unit of mass equal to 200 mg, 0.007055 oz or 0.006430 ozt, and it is used for measuring diamonds, gemstones and pearls
2. Diamonds can be separated from other gemstones by their hardness and their thermal conductivity.
3. A potentially destructive test to differentiate diamond from zircon, is to rub the table of a cut round brilliant diamond on silicone dioxide (quartz) sandpaper. Zircon will be scratched by the sandpaper while diamond will not
4. Diamonds and coloured gemstones may have a very high retail mark-up, sometimes as much as 3000%
5. The re-sale value of diamonds, outside of a retail outlet, are only a small fraction of the retail value
6. For example, a 0.25 carat, I2 clarity, H colour, round brilliant cut diamond may wholesale for $30 or less, but the retail price may be as high as $1000