When you visit a jewelry store every of us have noticed that gold jewelry is often made of metals that are called not just «gold» and «red gold», «white gold» or less common «green gold». Different whether it is metals or varieties of a conditional «basic gold»? We will try below to understand the difference between red gold yellow and all other «colored» varieties. Consider the question from the beginning.
The content of the article
- A bit about gold
- The difference between the red and yellow gold as well as other jewelry of gold alloys
- Comparison table
A bit about gold
When people began to mine gold is unknown. This rare and expensive metal had become a universal means of payment. In addition to the rarity and cost, they appreciated such qualities as beauty and resistance to aggressive environments, thanks to which the gold under normal conditions is not oxidized and retains its properties unchanged for a very long period of time. Ornaments of gold were made for several thousand years before Christ, and the first gold coins began Persian darici, named in honor of king Darius: they began to be minted in the late 6th century BC. Unlike red gold yellow is that it came later and used exclusively for the manufacture of jewelry.
Now briefly on the physical and chemical properties of the substance. Gold is an extremely heavy metal, its density is 19.3 g/cm3. Long time gold was considered the metal which is not soluble either in acids or in alkalis, but in the 14th century opened the possibility of dissolving it in Aqua Regia – a mixture of nitric and hydrochloric acids. Pure gold is extremely soft and malleable metal. For decorative purposes, for example, is made of the so-called gold leaf– sheets with a thickness of 100 nm (=0.0001 mm).
to table of contents ↑the Difference between red and yellow gold as well as other jewelry of gold alloys
Articles of pure gold is very soft, so to give them rigidity in the gold added to other metals. Depending on what metals and in what quantity is entered in the gold alloy, the gold and take the hue. Pure gold is yellow and white it becomes when added to a palladium alloy, Nickel or manganese. While base metals should not be more than 10 percent.
Red gold is when you add copper. There are a lot more options than in the manufacture of white gold. The most inexpensive is the red gold, where copper of about half. The more expensive alloy of copper, not more than 25 percent, in addition, they can have a complex composition. For example, gold can be 75 per cent, of copper, 22-24%, the rest silver.
Oh, and finally – the green gold. Initially, an alloy of gold and silver discovered by the Lydians (Lydia – state in Asia Minor) in the 9th century BC. The color of the alloy was greenish-yellow. Later experimentally obtained green gold, having a different composition. The basis, of course, remains gold, but the additives are different. It is not only silver, but also copper and cadmium; of course, the color and saturation of the alloy can vary.
to content ↑Comparative table
What is the difference between red yellow gold– it is clear from the table below.
The metal element of the periodic system of chemical sign Au
The yellow gold alloy with copper or with copper and silver
Exclusively for jewelry making