If you're looking for blue opals, then a Peruvian blue opal should be your gemstone of first choice. These gems are becoming more and more rare as time goes on, as they can only be mined n the Andes mountains near San Patricio, Peru. The unfortunate result is that some mines are producing different types of gemstones and dying them blue in order to pass these stones off as Peruvian blue opal. (Luckily, if you're looking for an opal inlay ring, this is less of a problem, as the fake opals tend to be used for beads). Opal inlay rings made with blue opals would be a beautiful addition to any jewelry collection.

There are a few ways for you to tell if the Peruvian blue opals you're looking at are not real. The most obvious clue is that fake blue opals will be relatively cheap - around $30-$40 for an entire strand of beads. Since the real opals are growing more and more rare, you would never be able to buy a string of beads for so cheap. After all, an opal inlay ring made with blue opal will be several hundred or even thousands of dollars.

Generally, if a company is making fake Peruvian blue opals, they will take white opals and then work to dye them. If you're worried that you might be buying fake blue opals, you should take a good look at the stones. In a lot of cases, you can tell that it is just a dyed white opal by looking with the naked eye. The blue coloring will be uneven, especially when you turn the stone so the light hits it from different directions. This is very useful if you're thinking about buying an opal inlay ring with blue opal, since you won't be able to tell by the price in some cases, and the weight will be difficult to determine due to the rest of the ring.