I have an ingot, just like a piece of silver in the movie. I don't know if it is copper or gold. Who can tell me how to distinguish it?
5 thoughts on “How to distinguish gold and copper”
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I have an ingot, just like a piece of silver in the movie. I don't know if it is copper or gold. Who can tell me how to distinguish it?
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1. Water and fire method
1, fire attack method:
The fire burning authenticity. "Real Gold is not afraid of fire" and cooled the jewelry through high temperature fire. If it is still yellow and does not deform, it is gold. It is a counterfeit product made of other metals.
2. Put the jewelry in nitric acid. If it is gold, it will be safe, and there will be no change. If it is copper, green smoke will emerge.
It, some of the traditional gold jewelry will not be very purity, more or less silver, even a bit of copper (sometimes a bit green), you can put it on the nitric acid diluted with water by water by water, which is doubled by 1 times nitric acid diluted with water. In the middle, heated and boiled for half an hour, remove the jewelry and wash it with water. At this time, the silver and copper on the surface have been removed.
If a little salt (sodium chloride) in the nitric acid just now, if there is a white precipitation (silver chloride) immediately, it means that there is silver in the jewelry. Please rest assured that processing does not damage your gold jewelry, on the contrary, it will make the color of the jewelry more beautiful.
. Eye viewing method
1. Clear the manufacturer and the color:
The surface layer of the gold jewelry should print the manufacturer and alloy purity (color), and the words should be clear. If there is no mark on the jewelry, or the mark is blurred, it should be suspected of the authenticity of the gold jewelry.
2, check color and change:
gold should have dazzling red yellow, its luster and color are enduring, the higher the color, the more beautiful the color, so people often say "Qiqing, Eight Yellow, Eight Yellow , Nine Five -Year Park ". The so -called gold jewelry referred to as other multi -metals can be recognized from color.
three, ear listening
Put the jewelry from the height of nature. If only the sound of "tab" is made, and there is no rhyme and no elasticity, it is the gold of the purity of 990 ‰. If the sound of sinking rhyme has a long elasticity, it means that it is not high, and the jewelry contains more copper and other metal components.
four, hand oscillating
that is more weight with your hand. The proportion of gold is 19.3, which is higher than silver, copper, aluminum, tin and other metals. The same volume of gold is 40%heavier than silver, 1.2 times heavier than copper, and 6.1 times heavier than aluminum.
In more weight, you can also identify whether it is faked with other metals. The easiest way is to know the weight with your hands to know true and false. As the saying goes, gold is "pressed" because the same volume of gold is much heavier than other metals such as copper and aluminum.
5, teeth bite method
tooth biting real gold. Gold hardness is low, soft, and bite with teeth, there will be traces, and other metals do not have this feature. Moreover, the higher the color of the gold jewelry, the softer it is, and it can also check the level of the color through a bend method.
If the color is low, there are more silver and copper components, so it is not easy to bend. With this method, you can recognize whether the gold jewelry is charged.
Extension information:
The single texture of gold (free formula) of gold is commonly referred to as gold. It is a popular precious metal. It has been used for currency, value preservation and jewelry for many centuries. In nature, gold appears in the golden blocks or golden grains, underground ore veins and accumulation layers in the rock.
gold is also one of the monetary metals. The single quality of gold is solid at room temperature, with high density, softness, light, and corrosion resistance. Its ductility is the highest among known metal.
Copper is a transitional element, chemical symbol CU, English COPPER, atomic order 29. Pure copper is a soft metal. When the surface is cut, it is red and orange with metallic luster, and the single matter is purple -red.
The good ductility, high thermal conductivity and high conductivity. Therefore, cables, electrical and electronic components are the most commonly used materials. They can also be used as building materials and can form many alloys. Copper alloy has excellent mechanical properties and low resistance, the most important bronze and brass. In addition, copper is also durable metal, which can be recovered many times without damaging its mechanical properties.
Reference materials: gold (one of the metal elements) _ 百度 贴 吧 (metal element) _ Baidu Encyclopedia
Different hardness. Gold: Pure gold is soft and low. It can draw light marks with nails. The teeth can leave the dental marks. The high -quality gold jewelry is lower than the soft color. Copper: The more bronze, the harder, the harder, the bending method can also test hardness, the pure gold is soft, it is easy to bend, the lower the purity, the less likely to bend.
The density. Gold density is large, and copper density is small.
grill with fire.
Gold: True gold is not afraid of fire, and the gold will be burned red with fire. After cooling, observe the color changes. If the surface is still the original golden color, it is pure gold.
Copper: It will be oxidized into black copper oxide under fire. In other words, if the color becomes darker or darkened to varying degrees, it may be copper. Generally, the lower the color, the stronger the color.
This is diluted.
Gold: It has a strong corrosion resistance,
placed in thin acids, there is no bubble.
Copper: Put it in thin acid, there are fakes with bubbles, because fakes are mostly mixed with zinc, which will react with acid.
This with acetaldehyde and CUSO4 solution.
Gold: In the same reason, gold is strong corrosive, and after heating, there is no response.
Copper: After heating, put it in the acetaldehyde solution. The redness is copper (that is, fake gold), add CUSO4 solution, and the red metal is precipitated by copper.
Use density; what is the quality of its quality first, and then measure its volume, divide the volume with the volume is density.
The volume can be drained, placed water in a known volume container, and then put the ingots in. After stabilizing, carefully take out the ingots, and reduce the remaining volume with the volume of water. Essence
The density of gold can be searched online, but it is generally not 100 % gold. As long as it is approaching, it means gold.
Bite with your teeth, the softer is gold, the copper is slightly harder (soil method)
or immersed in the water, the quality of the water overflowing water, the density of the water is 1 gram/cubic centimeter. Quality can get density
The density of gold is 19.3 grams/cubic centimeter, and the copper is 8.9 grams/cubic centimeter
The upstairs saying is more detailed. You should take a closer look at the length, width and height, and the accuracy should be as high as possible. Density = mass/(long x wide X height)
ers of the units are g, cm, cm, cm. If the result is close to 19.3g/cm3 is gold, if it is close to
8.9g/cm3 is copper