Characterization of Natural Precious Opal Using Modern Spectroscopic Techniques in Ethiopia: The Case from Delanta, South Wollo

Figure 1

Photograph images of opal samples mined from different mining sites at Delanta district: (a) Ds-1, (b) Ds-2, (c) Ds-3, (d) Ds-4, (e) Ds-5, and (f) Ds-6.