Rosa's heart was racing from the four cups of coffee she had just finished, but she thought she might be having a heart attack.
A carat is a unit of weight for diamonds and other gemstones. One carat equals 200 milligrams (0.200 grams). There are 453 grams in a pound (1,000 grams to a kilogram). Therefore, if your fiancee weighs 170 pounds, you have a 385,050-carat fiancee! A karat, when used with gold, is a unit of purity-- 24-karat gold is pure gold, but usually you mix gold with a metal like copper or silver to make jewelry (because pure gold is too soft). Each karat indicates 1/24th of the whole.
Unfortunately, pure gold is typically sold by the ounce while karat jewelry (kt.) is usually sold by the gram. Thus, we have to convert ounces to grams to find out the cost of the gold in a particular piece of jewelry. One troy ounce equals 31.1 grams. If pure gold is selling for $1700 per ounce in the metal markets, then one gram is going for $54.66 ($1700/31.1g).