True blue will never stain. What do you mean?

Real gold is not afraid of fire, which means that real gold is not afraid of being burned. Now it is a metaphor that a strong or upright person can stand a severe test.

Real gold is not afraid of fire, which does not mean that gold cannot be melted by fire, because the melting point of gold is really not high, but the chemical stability of gold is very high, and it is not easy to react with other substances, so there is no need to worry about oxidation and discoloration. Even in the molten state, it will not be oxidized and discolored, and it will still be golden yellow after cooling.

The meaning of this sentence is relatively simple to understand, that is, the stability of gold is unique among all metals and quite stable. Real gold is not afraid of fire, which does not mean that gold cannot be melted by fire, because the melting point of gold is really not high, but the chemical stability of gold is very high, and it is not easy to react with other substances. So now it also refers to noble personal qualities, and generally refers to the ability not to be afraid of what others say.

The nature of gold

Gold is the most malleable metal. A gram of gold can be made into a square meter of thin slices, or an ounce of gold can be made into 300 square feet. Gold leaves can even be thinned to translucent, and the light passing through them will appear green and blue, because gold has strong reflection ability to yellow and red light. Nano-gold materials are obviously different in ductility and extremely brittle. Gold foil with a thickness of 300 atoms must be electrostatically sucked up with red squirrel hair, otherwise it will be easily damaged.

Pure gold is tasteless because it is very resistant to corrosion (the taste of other metals comes from metal ions). In addition, the density of gold is quite high, and the weight of one cubic meter of gold is 19.320 tons. High purity gold single crystal can reflect infrared rays. The chemical properties of gold are stable, and gold does not react with oxygen at room temperature or under heating conditions. Only a special process can make gold oxide.