The buying guide to black opals /
Jewell, Bill.
Pearson, Grant M.
New South Wales.Department of Mineral Resources.
Australian Gem Industry Association.
[Sydney] : Dept. of Mineral Resources,
c1996.
Text in English and Japanese.
At foot of cover title: The Australian Gem Industry Association Limited.
"... partly based on material supplied by P.R. Evans with comments from the trade" -- T.p. verso.
Opals
Opals