Renfro N.D., Koivula J.I., Muyal J., McClure S.F., Schumacher K., Shigley J.E. (2019). Charts: Inclusions in natural, synthetic and treated opal. Gems & Gemology, Vol. 55, No. 2, pp. 244-245.
Renfro N.D., Koivula J.I., Muyal J., McClure S.F., Schumacher K., Shigley J.E. (2019). Charts: Inclusions in natural, synthetic and treated opal. Gems & Gemology, Vol. 55, No. 2, pp. 244-245.




