Opal is an original modern birthstone for the month of October. Some people call it the world’s most colorful gem because one stone can display a full spectrum of colors. Opal occurs many different varieties. The accompanying image is a black opal from Australia, but there are also fire opals from Mexico, honeycomb opals from Ethiopia, and colorful common opals from Peru. Lab-grown opals are available in a wide variety of colors and appearances for people who would like to obtain an attractive item for a lower price. Lab-grown opals are being sold today in many jewelry stores.