As the saying goes, "True gold is not afraid of fire", what color will the gold be shown after burning with fire?

Gold is still yellow after burning with fire. The maturity says that "real gold is not afraid of fire" is to say that gold jewelry is still yellow after burning, and it does not deform. If you burned it, it becomes orange -red, which is also normal. Because the so -called gold jewelry is not 100 % pure gold, you can reply to the original color after cleaning.
The authenticity of gold can generally look at the following aspects:

1. Seeing color
K gold, real gold, fake gold. That is, gold is better with red yellow, and the color is more than 95 %; the positive yellow color is about 80 %; the blue and yellow color is about 70 %; the yellow color is slightly gray and the color is about 50 %. Therefore, there is a formula for "seven greens, eight yellow, nine five red, and yellow leucorrhea ash.
If for the jewelry of Jiuzang, there is a saying that "copper turns green, silver turns black, and gold will never change color"
2, density
The density of gold is 19.32 grams / Cube centimeters are about double the same volume of silver, lead, and tin. Available formula: The mass (gram) of a certain gold jewelry (gram) is equal to density than the volume (cubic centimeter) of a certain gold jewelry (cubic centimeter). Seeking the density of the gold jewelry measured, the density is about 19.32 grams / cubic centimeter, it is pure gold or relatively pure gold, otherwise it is a non -pure gold or color difference gold (this method has no destructiveness to the jewelry).
3, folding hardness
gold has the characteristics of ductility and small hardness, and can be pressed into thin pieces of 12.7 microns. When the color is high, marks can be left with large head needles or nails. More than 97 % of gold jewelry, after twisting two or three times, wrinkles appeared at the bend, also called fish scales; about 95 % of gold jewelry, it felt hard when bending, and the fish scales were not obvious.
90 % of the gold jewelry, which is very hard when bent, without fish scales; gold jewelry containing more impurities, bend two or three times to break; Essence When using this method, the width and thickness of the jewelry should be considered. The thick and width should be hardened, and the thin and narrow ones are softer.
4, listening to the rhyme, watching elasticity
When the high -quality gold -gold entry knowledge jewelry is hit or throwing it hard, it emits a dull sound of "daedy, daemon" Elasticity, K gold has sound rhyme, sound, elasticity, the greater the elasticity, the more the rhyme, the more old, the worse the color.
5. Use the test goldstone to identify the color
The use of the gold -pairing card (the gold medal of the fixed color) and the subject's first jewelry on the test gold stone. Through the contrast color, the golden gold encyclopedia knowledge is determined. This method should be carried out under natural light and sunlight, and cannot be carried out under the direct sunlight and incandescent lamps.
6. Use acid dot
The golden roads that have been identified and paired on the testing stone, respectively, and test the nitric acid on the golden road with a glass stick. Therefore, the color is unchanged. If it is not gold or non -pure gold, the Golden Road disappears or changes.
The law of changes is "three fast, three slows", that is, the low color disappears quickly, and the high color disappears slowly; Depending on the disappearance of its golden road, compare cards can determine the color of gold jewelry.
This information
Golden physical properties
1, color:
The steam emitted when gold is melted is green; its gold powder during the smelting process is usually brown; Casting into a thin piece, it can convey green light.
2, ductility:
is extremely strong. 1 ounce of gold can be pulled into 50 miles long, and its ductility makes it easy to cast and is a good choice for making jewelry. Gold is the strongest in the metal.
3, forgedness:
INO. It can cause extremely thin and easy to roll up. 1 ounce of gold can be hammered to 4 million -foot thick and 100 square feet. The ancients hammed it into thin slices to decorate the temples and the palace. These can explain the strong flexibility and forgedness of gold.
The color of gold is golden yellow, metal luster, difficult to break down. The hardness is 2-3, the pure gold is 19.3, and the melting point is 1064.4 ° C; it has good ductility and can be pressed into thin foil. It has extremely high heat transfer and conductivity. The resistance of pure gold is 2.4P. Pure gold has good anti -chemical corrosion and is the best electroplating material.
Reference information Source: Baidu Encyclopedia-Gold

Gold, because the chemical properties are quite stable, even at a high melt temperature, it will not be oxidized by oxygen in the air.
Therefore, after baking with fire, if it is not carbon, it is still golden yellow. If the carbon is carbon, it is black, but the wipe with a rag is still golden yellow.
It, I like the bathtubs and toilets made of gold on the picture. In the newly bought house, these two are installed, and I have nothing to do.

The temperature is high, and of course it becomes red, because there is no 100 % pure gold, it will naturally change color when burning