Opal from Namakwa District Municipality, Northern Cape, South Africa
South Africa | |
| Cairncross, B., Dixon, R. (1995) Minerals of South Africa. Geological Society of South Africa, Linden . |
| Eriksson, P.G. (1997): Mineralium Deposita 32, 419-422. |
South Africa | |
| Cairncross, B., Dixon, R. (1995) Minerals of South Africa. Geological Society of South Africa, Linden . |
| Eriksson, P.G. (1997): Mineralium Deposita 32, 419-422. |