Home > Gemological Info. >
Weights and Measures

Weights and Measures
Gemstone Enhancements
Gem News
Carat Weight


24K gold is pure gold. All other karatages of gold have a portion of alloys that reduce the pure gold content. For jewelry, this is done to increase the hardness, durability, and color of the metal. 18K gold is 75% gold and 25% alloy. 14K gold is 58.3% gold. 24K gold (100% gold) is very soft and has a very distinctive yellow color. The most common alloys of gold are mostly silver and copper for yellow gold and mostly nickel and zinc for white gold. Platinum is commonly alloyed with either iridium or palladium and it has the 'whitest' appearance of all the white precious metals. I use 14K yellow and white gold, 18K yellow gold, platinum, and some karat colored golds for most of my jewelry, depending on the appearance and use for that piece (yellow gold above 18K becomes soft for ring use). I also use higher karat gold from time to time for appearance. Certain pieces can be created using the gold karatage you prefer.



All gemstones are weighed by the carat.
1 carat = 0.2 grams or 5 carats = 1 gram
Wherever possible, I have tried to list the carat weights of the gems in each piece of jewelry. They are listed to the hundredth of a carat. Just as a tidbit, the system of carat weight is based on the carob seed. In the ancient Middle East, items to be weighed would be placed on a balance opposite a number of dried carob seeds (from the carob or locust tree) which tended to have the same weight. Carob, hence carat.



Within the jewelry trade, the metric system is used for most measurements. Pearl size is measured within a half of a millimeter tolerance (6.0-6.5mm for example). Gemstones are measured in millimeters and many of the shapes have certain traditionally calibrated sizes (faceted ovals can be 10 x 8 mm, 9 X 7mm, 8 x 6 mm, etc. for example). One inch = approx. 25.4mm. To better visualize millimeter size, a penny measures about 19 mm across. I find that, over time, referring to a handy ruler (both American standard and metric measurements on it) helps make gemstone measurements easier to visualize. For most of the pieces in the jewelry collection, I have tried to measure the most visually significant parts that face up to help you get a perspective for the size of each piece of jewelry.