Perhaps, verifying that gold bites gold is one of the ways to distinguish the authenticity of gold! We usually use four methods to distinguish the authenticity of gold: First, the color of gold is seven green, eight yellow and ten red in nine purple. It means that the gold content of cyan yellow is 70%, yellow is 80%, purple yellow is 90%, and red yellow is almost 100%. Second, look at the proportion. Gold has the largest specific gravity among known substances, with the specific gravity of 19.37, which is as heavy as brass. The volume of copper is much larger than that of gold and red gold with the same weight. Experienced people can know a thing or two by looking at the color and weighing it. Third, the specific hardness of red gold is the smallest. You can use teeth to bite marks and draw lines with pins. Fourth, burning real gold is not afraid of fire. After burning in the flame, it is still golden yellow, and other metals will be oxidized and discolored when burning. In addition, real gold is insoluble in a single acid (such as hydrochloric acid and sulfuric acid), and other metals are not as good as gold. Verifying that gold bites gold is one of the ways to distinguish the authenticity of gold! We usually use four methods to distinguish the authenticity of gold: First, the color of gold is seven green, eight yellow and ten red in nine purple. It means that the gold content of cyan yellow is 70%, yellow is 80%, purple yellow is 90%, and red yellow is almost 100%. Second, look at the proportion. Gold has the largest specific gravity among known substances, with the specific gravity of 19.37, which is as heavy as brass. The volume of copper is much larger than that of gold and red gold with the same weight. Experienced people can know a thing or two by looking at the color and weighing it. Third, the specific hardness of red gold is the smallest. You can use teeth to bite marks and draw lines with pins. Fourth, burning real gold is not afraid of fire. After burning in the flame, it is still golden yellow, and other metals will be oxidized and discolored when burning. In addition, real gold is insoluble in a single acid (such as hydrochloric acid and sulfuric acid), and other metals are not as good as gold.