From the beginning of human civilization, gold has been prized for its great magnificence and brilliance. Hence, many societies valued, extracted, guarded, and imagined that this shining metal was liked by the gods as much as man. Gold is the source of many myths, many superstitions and human searches.
Ingots of pure yellow gold are the most common to our eyes, but today the precious metal is available in a wider variety of shades and purities. Because man has learned long ago to mix 24K gold with the right metals to make soft pure gold much stronger, more suitable for the household and jewelry. This process in jewelry is called “alloying” – when different alloys and specific additives give gold the desired fineness or color.
White gold is made by fusing pure gold with white metals such as palladium or silver. In addition, white gold is often plated with rhodium, another precious metal that protects the surface of gold.
Rose (Red) gold
Adding copper in the appropriate proportion to the pure gold alloy gives a subtle tone of rose gold, also known as “nude” (body-colored gold).
Various shades that are unusual for the eye (e.g. blue, purple) are extracted with the help of patina or oxides. Dark gold takes on a hint of cobalt oxide.
The heaviness of gold is estimated in Troy ounces (1 Troy ounce = 31.1034768 grams), but its purity is estimated in ‘karats’.
The word “carat” was first used in English in the 15th century., although it originated from the Italian carato, which followed from the Arabic word qīrāṭ (قيراط), which was probably borrowed from the Greek word kerátion (κεράτιον), the seed of the carob plant. So, it was believed that the weight of the gold mass was similar to that of carob seeds, although in fact this was not true.
- In the 1570 carats, diamonds were also weighed.
- And in 1907, it was decided to keep 200 milligrams (exactly one-fifth of a gram) of carat at the International Committee on Weights and Measures in Paris.
Caratage is an estimate of gold’s purity (and its content in alloys with other additives). Perhaps the most popular are the three gold proportions in the alloys: 24K, 18K, and 14K;
24K gold is considered pure gold, without additives and impurities. It is soft, so when “diluted” it turns into 18K gold – when the alloy contains 75% pure gold and 25% different metals (usually copper or silver). Adding less pure gold (about 58.5%) according to the formula will make the alloy even harder and make it 14K gold.
The base caratage for a thing to be called gold changes by country. In the US, 10 carat is the legitimate least acknowledged norm of gold caratage, 14 carat being the most well known. In France, the UK, Austria, Portugal and Ireland, 9 carat is the least caratage allowed to be called gold. In Denmark and Greece, 8 carat is the lawful least norm to still be called gold.
Let’s assume you buy a ring that is 14K gold. Since the number measure of karats you can have is 24K, divide the 14 Karats by the 24. You will get .583. This implies that the gold is 58.3% unadulterated.
Some Terminology Surrounding Gold:
- Assay/Hallmark: An examination (by professionals) that demonstrates gold metal quantity and quality in a substance/alloy. Upon identifying the gold, a symbol or mark is stamped on a piece of the precious metal that certifies its standard of purity.
- Hallmarking: standardized marking of a product or metal ingot. In Lithuania, this is done by the state institution LPR (Lithuanian Assay Office). In the world – very different, completely from the country. In Germany, as in the US, this is done by the producers themselves, e.g. in Spain the state does the hallmarking itself.
- Bullion: Valuable/noble metals in a mass, uncoined structure like gold bars, considered in mass instead of their worth.
- Carat: Not to be confused with Karat in North America, a Carat is a unit of weight used for precious stones. One carat is equal to 200 milligrams. Outside of North America, Carat is used in the same context as Karat.
- Karat: Unit of measurement for the fineness of gold, with the higher numbers containing more gold and 24K being the finest.
- Embossing mark: a symbol or mark embossed on a bullion or a piece of jewelry attesting to its standard of purity. Also – the mark of the author, workshop, manufacturer (in Lithuania the latter is called a name-mark).
- Millesimal Fineness: A system used to show the purity of precious metals by parts per thousand rather than karats.
- Troy Ounce: 31.1034768 grams, or approximately 1.09714 standard “avoirdupois” ounces.
- Troy Weight: A system of measurement used for gemstones and precious metals, where a full Troy pound consists of 12 “troy” ounces rather than the 16 “avoirdupois“ ounces in a standard pound.
Table Showing Common Compositions Of Gold Alloys:
|Caratage||Gold(Au)||Silver (Ag)||Copper (Cu)||Zinc (Zn)||Palladium (Pd)|
|White Gold||18K||75%||0%||0%||0%||25% (or Pt)|
Standards And Common Hallmarks:
- .375 = 9 karat (England and Canada)
- .417 = 10 karat
- .583 (.585) = 14 karat
- .750 = 18 karat
- .833 = 20 karat (Asia)
- .999 (1000) = 24 karat unadulterated gold
Strictly speaking, 14 karat ought to be 583 (14/24 = .583333), yet most producers have taken on the European act of making 14 karat gold, somewhat more gold-containing than would be normal for 14 karat. In this manner, the fineness mark is 585 in most 14 karat gold products.
Additionally, 24 karats in gold ought to be 1.0 (24/24 = 1.00). Nonetheless, there is probably going to be trace amounts of pollutants in any gold, and it must be refined to a fineness level of 999.9 parts per thousand. This is expressed as 999.9 with 999.95 being the maximum possible purity according to various countries’ standards.
Acknowledged standards on gold purity fluctuate from one market to another. In China, Chuk Kam (which is Cantonese for ‘unadulterated gold’ or in a real sense ‘full gold’) is characterized as 99.0 percent gold, with a 1.0% allowance of additives.