Peruvian Opals come from the San Patricio area near the Andes Mountains of Peru. The Peruvian Opal is the national stone of Peru, and was considered by the Incas as a gift from Pachamama, the goddess of Mother Earth.
They are associated with copper mines, and as copper has become more expensive, the mining of Peruvian Opals has generally stopped, in favor of mining the copper.
These opals are made up of hydrated silicon dioxide, with small inclusions of chrysocolla, which is a copper silicate. The chrysocolla gives the opals their soft blue color, which has sometimes been compared to the blue of the Caribbean Sea.
Many of these stones are translucent, so that you can see light coming through them. Unlike other opals, the crystalline structure of these is unorganized, so that you don't get flashes of different colors. Instead, you get a very tranquil blue color.
The Mohs hardness of these opals is 5.5 to 6, making them somewhat harder than many other opals. However, they are very susceptible to heat, and excessive heat can make them fracture or lose their color.
In the metaphysical sense, Peruvian opals are said to be associated with the throat chakra, and are said to promote and facilitate communication, creativity, and the free flow of ideas.
We have a number of Peruvian opal cabochons on our Heart of Stone Studio website, www.heartofstonestudio.com.