How to tell if coral jewelry is real

Now we have found the coral jewelry in ancient grave sites from the  back as 10,000 B.C. But from that time there are some pretty convincing fakes out, such as : plastic, bone, shell, fossil ivory, howlite and onyx were made the imitation coral. The first step in determining if a piece of jewelry is real or fake is its weight. Real coral jewelry is heavier than imitations.
The following is about the method of testing coral jewelry
The first:: if you have the coral jewelry , please put the coral piece into a small ceramic bowl and soak it with cow's milk.
The second is: If the coral jewelry is real, then it will color the milk, when you put the jewelry in the milk at the common temperature for 1 to 2 hours, If the piece is fake, the whiteness of the milk wont changed.
The third is: you can place a drop or two of nitric acid or lemon juice on the coral, like the back of a piece of the coral jewelry. If the coral is real, you will find the spot will effervesce and form tiny bubbles on the coral surface.
With the real coral identification guide, you can easily tell if the coral is real or not. Please keep the identification in mind and apply it when you buy coral jewelry.