Pink Opal

Peru is known for pastel pink common opal, mainly from the Andes, and it is often cut into beads and cabochons. Studied material comes from the Acari mining area near Arequipa. Translucent pink opal also occurs in Mexico (Mapimí in Durango and Michoacán), and pink common opal is reported from Western Australia and Oregon. Fritsch and co-authors suggest that the opal-CT, palygorskite and organic pigment association points to a former lake environment in a volcanic region.

Pink opal has the low refractive index and specific gravity of opal and no play-of-color. In Peruvian samples, palygorskite-bearing pink opal-CT has a greasy to waxy luster and splintery fracture, while palygorskite-free pale pink opal-C has a duller, porcelain-like luster and conchoidal fracture. The color has been attributed to an absorption near 500 nm linked to fossil organic quinone pigments held by the palygorskite fibers. Chalcedony is harder (Mohs 6.5 to 7) and denser (2.58 to 2.62) than opal. CIBJO notes that some opal on the market, including pink Ethiopian opal, is dyed.

Opal is fairly soft and brittle and contains water, so it may crack after sudden or extreme changes in temperature or humidity. CIBJO advises protecting opal from abrasion, thermal shock and harsh chemicals, keeping it away from direct sunlight and other heat sources, and cleaning it with a damp cloth only; ultrasonic cleaners should not be used.

The Japanese retailer Pascle gives pink opal the meanings it associates with opal in general, saying it is traditionally believed to encourage creativity, and also links it with expressing feminine charm and with love. Pascle lists it among October birthstones in Japan. These are retail traditions, not verified properties.