Opals Revisited
In the 1980s, the author and his wife, Corky, acquired large quantities of Virgin Valley “wet” opal specimens displayed in glass domes with water and other specimens immersed in silicone oil. The domes had black rubber stoppers on the bottom. The mine representative had put them in water and silicone oil to enhance their beauty, since wetting the surface gives the illusion of a polished gem specimen.
Opal is a hydrated amorphous silica, and those with a high water content tend to craze and crack if left to dry. If a specimen is inclined to craze or crack, placing it in a liquid does not stabilize it or heal the cracks within, but it does delay the “day of reckoning” when the opal eventually deteriorates.
The specimens displayed in the domes with water began forming deposits, and within months the water became cloudy and the domes were crusted with precipitate from dissolved minerals. Those in silicone oil fared better, but eventually they too deteriorated, with the silicone oil taking on a yellow cast from the black rubber stoppers, which appeared to coat the opals with a yellow crust (figure 1).
After years of changing the water and silicone oil, the cleaning and repackaging eventually became very time-consuming. The author removed all the wet specimens from their domes, cleaned and wrapped them in paper towels, and put them in boxes. The boxes with the now-dry opal specimens were packed away and stored in the garage, where they remained for more than 27 years.
In July 2019, the author found the boxes containing these beautiful and long-forgotten opals. The results were astonishing. They had not fallen apart, and they looked more stable than they had when dried and put away. The cracks were still there, but the look was different. They looked like they could be worked—if not on the wheels, then with a flex shaft. The first opal that caught the author’s eye (again, see figure 1) was cleaned and worked (figure 2). The completed piece, shown in figure 3, is named “Bonnie Jean.” There are many more to finish, and they are dry and unlikely to craze or crack any further.
