Opal can be divided into black opal, white opal, and yellow opal based on its color, of which the most expensive is black opal. In order to raise the grades of the lower price white and yellow opal and reap Gregory, artificial means of changing color is on use. The main method is cooked it in sugar or molded in plastics, then the white opal will became the black one.
Opal is an important part in the jewelry market ,always matched with the earrings ,bracelet ,and necklace .buy a real opal jewelry is the wish of every customers .there are two simple methods to tell you whether your opal is true or false .
First, you can test it in water, specific gravity of the opal which has cooked in sugar and plastic molded will lighter.
Second, it also can recognize by injecting the opal with a heated needle. The hot needle can not enter the Natural Opal, but the molded opal can be go through and release a strange smell when the plastic is heated.
The two methods, have you understood? Quickly try it!