Ricco Gallery

Carat is a mea­sure of weight for pre­cious stones, like dia­monds.
Karat is a mea­sure of gold purity.
Car­rot is some­thing you eat.
They are all pro­nounced the same way, but they mean dif­fer­ent things.

What is a carat?

Carat is a weight mea­sure used for pre­cious stones. There are five carats in a gram, so each carat is two tenths of a gram. A five carat dia­mond weighs about the same as a one dol­lar bill. Diamond weight is some­times expressed in “points.”  One hun­dred points is one carat, 10 points is a tenth of a carat, and so on.

What is a karat?

Karat is a mea­sure of gold content. 24 Karat gold is pure gold. 12 Karat gold is an alloy , mean­ing that half the metal is pure gold and half is some other metal (usu­ally a mix of sil­ver and cop­per and smaller amounts of other metals). 18 Karat gold is 18/24 or three-fourths pure gold with the other fourth made up of other met­als. An alloy is a mix of metals.

To find the per­cent­age of pure gold in a piece marked in karats, divide the karat num­ber by 24. Thus, 14K is 14/24 = .583 pure gold, .417 some­thing else. A 14K piece has 58.3% gold in it. The rest is some­thing else, such as sil­ver, cop­per, nickel, zinc, etc.

To find the weight of pure gold is in a piece of jew­elry, weigh the piece and mul­ti­ply by the frac­tion of purity indi­cated by the karat mark. For exam­ple, a ring that is marked 14K weighs 30 grams, so the gold con­tent is .583 times 30 = 17.5 grams gold, with the rest something else.

To find out how much that is worth on the gold mar­ket, go to www.kitco.com and find the cur­rent value.. Today, August 15, 2011, gold is 1739 dol­lars per ounce.  One ounce (troy weight, see below) = 31.1 grams. Using the exam­ple above where you found the weight of gold to be 17.5 grams, divide 17.5 by 31.1 to find the frac­tion of an ounce that rep­re­sents. Thus, 17.5 divided by 31.1 = .562 ounces. Mul­ti­ply that num­ber by the gold price to find the mar­ket value of the gold in the piece: .562 times 1739 = 977.32 dollars.

Troy weight is is used for pre­cious met­als like gold. Avoir­du­pois weight is for car­rots. One ounce troy = 31.1 grams. One ounce avoir­du­pois = 28.35 grams. There are 12 troy ounces in a troy pound. There are 16 avoir­du­pois ounces in an avoir­du­pois pound. Although you can see that there are dif­fer­ent def­i­n­i­tions of an ounce, a gram is a gram is a gram. One thou­sand grams is always a kilo­gram. One kilo­gram is approx­i­mately 2.7 pounds troy and 2.2 pounds avoirdupois.

Another com­mon weight unit for gold is the pen­ny­weight: there are 20 pen­ny­weights in a troy ounce, so 20 pen­ny­weights (abbre­vi­ated dwts) equals 31.1 grams. Divide 31.1 by 20 to find grams per pen­ny­weight (1.55 gm per dwt) or 20 by 31.1 to find pen­ny­weights per gram (.643 dwt per gm). Pen­ny­weights are not used for sil­ver, but they are for plat­inum and pal­la­dium (as well as gold.)

Stamp­ing: By law, items made with pre­cious met­als (like gold, sil­ver, plat­inum) must have a karat mark, made by a spe­cial stamp. Karat stamps can be bought by any­one at a sup­plier of jew­elry tools such as Rio Grande.  They can be used to stamp any kind of metal, so just because some­thing has a karat mark doesn’t mean that it is nec­es­sar­ily what the mark indi­cates.  By law, the mark has to be accom­pa­nied by another mark, indi­cat­ing who made the item, so you know who to blame if there is a dis­crep­ancy. Even so,  there have been cases of “skim­ming” or “under­karat­ing,” espe­cially by for­eign sup­pli­ers since their items are rarely tested for gold con­tent. The basic rule is to know your sup­plier. In that area, the best bets are small pro­duc­ers — inde­pen­dent artists — like me.

Types of Gold:

When you’re con­sid­er­ing a pur­chase of gold jew­elry, it’s easy to get con­fused by the many descrip­tions that include the word “gold.”  Here’s what the most com­mon phrases actu­ally mean:

Gold Filled, also called Gold Over­lay, refers to a layer of at least 10-karat gold that has been per­ma­nently bonded by heat and pres­sure to one or more sur­faces of the under­ly­ing metal (such as brass) then rolled or drawn to a pre­scribed thick­ness. The karat gold weight must be at least 1/ 10 of the total weight. This type of gold might be stamped 1/10 10K GF.

Gold Leaf is usu­ally pure gold metal that has been pounded into paper thin sheets.

Gold Col­ors:

Pure gold has a char­ac­ter­is­tic color that is unmis­tak­able and unlike any­thing else. When alloyed, gold can take on a num­ber of col­ors, includ­ing: white, pink, green, and even purple.

Yel­low gold is gold alloyed with vary­ing per­cent­ages of sil­ver and cop­per plus smaller amounts of other ele­men­tal met­als like zinc, at times. It is the most fre­quently used type of gold.

White gold is alloyed with a large per­cent­age of sil­ver, or a selec­tion of other white met­als, typ­i­cally nickel.   White gold is highly reflec­tive and does not tar­nish. The ancient term for it was Elec­trum. Its use pre­dates that of Pal­la­dium and Plat­inum. A rel­a­tively new white gold is made with alloys of pal­la­dium instead of nickel. Since some peo­ple are aller­gic to nickel, this is a wel­come addi­tion to the fam­ily of alloys. Ricco uses pal­la­dium white golds exclu­sively and never plates on top of them.

Rose gold is made by alloy­ing gold with cop­per, a red metal, and sil­ver.  The more cop­per in the alloy, the red­der the color.