Ao contrário da crença popular, quando você compra uma joia de ouro, geralmente não é feito de ouro puro. Em vez de, quase todas as joias de ouro são feitas de uma liga criada pela combinação de ouro puro com uma variedade de outros metais.
A razão para isto é que o ouro puro é muito macio. If engagement rings, earrings and other jewelry were made using pure gold, they’d scratch, scuff, dent and warp extremely easy, often just from brushing against another surface.
There’s also the color issue — instead of the warm gold color that most of us associate with gold jewelry, pure gold is actually closer to orange in color.
Devido a esta, modern gold jewelry uses gold that’s mixed with other metals. The purity of this gold is measured using the karat system, which provides information on what percentage of any type of gold is made up of pure gold.
Gold karatage is expressed in parts out of 24. Por exemplo, pure gold is 24K, as all 24 fora de 24 parts consist of pure gold.
18K gold consists of 18 parts pure gold mixed with 6 parts other metals. Depending on the color of the gold (por exemplo, ouro branco, yellow gold or rose gold), these metals could include nickel, prata, cobre, zinc and palladium. Expressed as a percentage, 18K gold is 75% ouro puro.
14K ouro, por outro lado, consiste em 14 parts pure gold mixed with 10 parts other metal, with the other metals varying based on the gold’s color. Expressed as a percentage, the pure gold in a piece of 14K gold jewelry accounts for 58.3% of the total metal.