Andean or Peruvian opal is hard to obtain and difficult to work. To counterbalance this, it comes in lustrous transparent or opaque pastel blues, greens, browns and sometimes pinks.
Here’s something we downloaded from the internet about this semi-precious stone:
Andean Opal, also known as Peruvian opal, is mined in the Peruvian Andes and is an hydrous silica gel. It differs from other opals in that it has no fire or play of colour. Rather, Andean opals come in gentle pastel tones of aquamarine, sea-green, pink and tan. These opals range from opaque to translucent, and depending on how the stone is cut, the colour will either be clear or show the stone’s matrix and inclusions. (Like agates, some Andean opals show the scenic fern-like dendritic inclusions.)
Mined as thick veins in host rocks, the green-blue Andean opal’s colour comes from trace amounts of copper. The pink opal derives its colour from trace amounts of included organic compounds known as quinones.
In pre-Hispanic Peru, the ancient Incas considered these opals sacred to the Earth goddess Pachamama, who is still worshipped in Peru, and has always been known as a generous deity, the goddess of fertility and good luck. Andean opal, which is considered a gift from the goddess as well as part of her domain, has a long history of use in ceremonial objects and jewellery.