Hundreds of vendors from dozens of countries converged in Tucson, Arizona, for the annual Gem and Mineral Show, where the ...

Beryl’s crystal structure is more complicated than corundum’s because of the additional elements in the formula, but each aluminium ion is again surrounded by six oxygen ions. Pure corundum ...

Beryl's crystal structure is more complicated than corundum's because of the additional elements in the formula, but each aluminum ion is again surrounded by six oxygen ions. Pure corundum and beryl ...