Zincblende is an alternative name for sphalerite, a mineral containing cubic crystals.
1)Zinc ore is concentrated by the process named forth floation to about 55% 2 )concentrated ore is roasted in the presence of air to convert the ore into Zinc Oxide ZnS + O2 ---> ZnO + SO2 3 )Zinc Oxide is reduced to zinc in the furnace by coke ZnO + C ---> Zn + CO2
Option A: see RefractiveIndex.INFOOption B: If you have access, see the articlehttp://dx.doi.org/10.1016/S0022-3697(96)00219-3which has both theoretical and experimental data. It depends on frequency, of course, and also whether you're talking about zincblende or wurtzite GaN. For wurtzite, it also depends on direction.If I'm reading Figure 4 correctly, the zero-frequency index of refraction is supposed to vary between about 2.25 and 2.4, depending on structure and direction.The article is from 1996, so presumably there are newer, better papers since then.
Metallic solid