Gold and Metals
What does the term "karat" mean in the jewelry world?
In the jewelry sector, unlike the diamond and gemstone sectors, the term "karat" [with a K] refers to a grading scale that measures the amount of pure gold contained in alloys, which are a mixture of two or more metals. In the jewelry making field, the number that appears next to the term "karat" denotes the purity grade of the gold. The highest purity grade on the scale is represented by the number 24, while the lowest gold grade is represented by the number 9. For example, when we say that a piece of jewelry is made from 18K gold, this means that 18 of the alloy's 24 parts are pure gold, or in other words – 75% pure gold.
What are the most common colors of gold in the jewelry industry?
Practically speaking, it's possible to create gold alloys in an exotic variety of colors. But the jewelry industry nevertheless continues to focus on three basic colors only: yellow, white, and red. The different colors are created when different amounts of copper, pure silver, zinc, and nickel are added to pure gold. You should keep in mind that in jewelry made from 18K gold the colors red and white don't show up because of the heavy presence of pure gold. This is the reason why 18K white gold is usually plated in rhodium.
What is rhodium plating?
Rhodium is a light silver-colored metal from the platinum family. Rhodium is used to plate gold jewelry, or parts of it, to give it a silvery shade or to highlight places set with gemstones. Rhodium's silvery color gives the piece of jewelry a sparkling, expensive appearance. However, because the rhodium plating technique doesn't allow for a thick layer, it tends to wear off relatively quickly in rings and bracelets. In this case, customers can contact a jeweler and ask that the rhodium plating be renewed.
How can I be sure that the jewelry I've just bought is really made from gold?
First of all, it's always advisable to buy jewelry from the manufacturer or a reliable store. Any jeweler can also conduct a basic test using an acid test kit. This test gives a very general answer, and to check absolutely, the jewelry should be sent to a lab for testing. A scientifically approved test can be run at companies that produce precious metals.
What stamps should buyers look for when buying a piece of jewelry in Israel?
The Standards Institution of Israel (SII) rules stipulate that every piece of jewelry manufactured in Israel carry three separate stamps: the manufacturer's logo; the purity grade of the alloy from which the jewelry is made – the karat, in other words; and the SII stamp, a logo in the shape of David's lyre.
Why does platinum jewelry cost much more than gold jewelry?
There are a number of reasons for the high cost of platinum jewelry compared to gold jewelry:
1) Platinum is a much rarer metal than gold, and so its raw price is much higher
2) Only 5% copper is added to platinum to make jewelry, whereas gold is "watered down" by 25% or more
3) Platinum's specific gravity is 40% (!) heavier than a 14K gold alloy
The Stone Setter
What is the stone setter's role in preparing jewelry?
The stone setter's role is to fit the diamonds and gemstones to the metal of the jewelry. The setter uses the jewelry settings created by the jeweler and sets the diamonds or gemstones in them. The setting process is generally complicated, containing a number of steps: Fitting, assembly, setting, and finishing. There are also types of stone setting in which the setter creates the setting, and not the jeweler.
Is the setter responsible for the stone during the setting?
The setter is not responsible for the gemstones or diamonds during the setting process, whether it’s a stone that costs a few dollars or a gem that costs thousands. This unwritten law, like many others in the world of diamonds and jewelry, is respected almost everywhere in the world. It comes from the fact that the setter has no control over the stone's seen or unseen stresses and cracks. It's unreasonable that the setter who earns less than a hundred dollars for setting a stone would have to compensate the owner thousands or tens of thousands of dollars. It's interesting to compare this rule to the diamond polisher's limited responsibility during polishing.
