All fire opal rings are made of silicon dioxide and water. The amount of water varies and determines the fragility of the individual stones. This gemstone is formed when silicon dioxide gets wet and turns into gel. This gel substance then works its way into the open space between the rock and the cave. An opal is formed as soon as it is set.Typically, gemstones hold about 10% water content which makes it quite soft and delicate. They come in different colors of blue, green, pink, black, white, red, yellow and orange.This stone is tempting for its color play which shows the brightness of color when light bounces from a silica sphere. Fire opal is a gemstone which is less desirable for its color play because it is for its original color. As the name implies, this stone is burning with red, yellow and orange. Finding a fire opal pendant with warm shades as well as color play offers the best of both worlds.