Mineralogical Magazine, v. 38, p. 424 - 434. Eyles, W. C., 1953. Thoughts of an Opal Buyer. They still dig for opal at Lightning Ridge. Lapidary Journal, v. 17, no. 7, p. 736-738.
Opal boom continues.
Lapidary Journal, v. 17, no. 7, p. 755.