The opals I use are certified by the GIA as being a true synthetic opal, which means it has all the properties of a natural opal. The colors in the opal are produced by the light and are not dyed or produced artificially. The difference between synthetic and natural opal, is that the slow process that a natural opal goes through is sped up in a lab for about a year to produce synthetic opals. Because they contain at least 80% silica, they are not as fragile as natural opals and will not crack, dry out, yellow, or lose its fire over time. These qualities make them a great alternative for everyday jewelry. Plus, the colors they come in are amazing! I work directly with the opal manufacturer to have them custom made to my specifications.