How to identify gold and copper

One, water and fire method

1, fire attack method:

Fire recognition of authenticity. "Real gold is not afraid of fire" will be cooled by high-temperature fire jewelry, if it is still yellow, not deformed, is gold, which is the proverbial "fire to see the real gold"; if it becomes black, it is not the real gold, but made of other metals counterfeit products.

2, "water" attack method:

That is, use nitric acid to identify gold authenticity. The jewelry will be placed in nitric acid, if it is gold is safe and sound, there will be no change, if it is copper, it will be green smoke.

In addition, some traditional older gold jewelry purity will not be very high, more or less clip a little silver, and even a bit of copper (sometimes the surface is a little green), it can be placed in water diluted 1 times the nitric acid, heating and boiling for half an hour, the jewelry will be taken out, washed with water, at this time, the surface of the silver and copper has been removed.

If you add some salt (sodium chloride) to the nitric acid just now, if there is a white precipitate (silver chloride) immediately, it means that there is silver in the jewelry. Please rest assured that this treatment will not damage your gold jewelry, on the contrary, it will make the color of the jewelry more beautiful.

Two, the eye method

1, recognize the manufacturer and color:

Golden jewelry surface should be printed manufacturers and alloy purity (color), and the words are clear. If there is no print on the jewelry, or the print is blurred, should be suspicious of the authenticity of the gold jewelry.

2, check the color and change:

Gold should be dazzling reddish yellow, its luster and color is enduring, the higher the color, the more beautiful the color, so it is often said that "seven green, eight yellow, nine or five red". To other polymetallic pseudo-called so-called gold jewelry, from the color can be identified.

Three, ear method

Listen to the sound of defense components. Will be attached to the jewelry from a high place naturally fall, if only issued a "bla bla" sound, and sound without rhyme without elasticity, is the purity of why 990 ‰ of gold. If the sound sinking rhyme long elasticity, indicating that its color is not high, jewelry containing copper and other metal components more.

Four, hand weighing method

That is, the weight of the hand weighing comparison. The specific gravity of gold for this 19.3, 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, 6.1 times heavier than aluminum.

By comparing the weight, you can also identify whether the other metal counterfeit gold jewelry. The simplest way is to use the hand to weigh the weight, you can know the true or false. As the saying goes, gold "pressure hand", because the same volume of gold than copper, aluminum and other metals much heavier.

5, teeth bite method

Teeth bite identify real gold. Gold hardness is low, relatively soft, gently bite with your teeth, there will be traces of other metals do not have this feature. Moreover, the higher the color of gold jewelry, the softer, but also by bending the way to check the color of the high and low.

If the color is low, which contains more silver and copper components, it is not easy to bend. With this method can identify whether the gold jewelry is substandard.

Expanded:

Gold in its monomers (free form), commonly known as gold, is a popular precious metal that has been used for many centuries as a currency, a security, and as jewelry. In nature, gold occurs as a single substance in the form of nuggets or grains in rocks, underground veins and alluvial deposits.

Gold is also one of the monetary metals. Gold is solid at room temperature, dense, soft, shiny, corrosion-resistant, and has the highest ductility of any known metal.

Copper is a transition element, chemical symbol Cu, English copper, atomic number 29. pure copper is a soft metal, the surface just cut for the red-orange with a metallic luster, the monomers were purple-red.

Good ductility, thermal conductivity and high electrical conductivity, so in the cable and electrical, electronic components is the most commonly used materials, can also be used as building materials, can be composed of numerous kinds of alloys. Copper alloys have excellent mechanical properties and low electrical resistivity, the most important of which are bronze and brass. In addition, copper is a durable metal that can be recycled many times without losing its mechanical properties.

References:

Gold (one of the metallic elements)_Baidu Encyclopedia ? Copper (one of the metallic elements)_Baidu Encyclopedia