The most common kind of crystalline alumina, α-aluminium oxide, is referred to as corundum. When trace factors make it show up purple it is named ruby, but all other colorations tumble underneath the designation sapphire. Corundum incorporates a trigonal Bravais lattice with an area team of R-3c (range 167 during https://lanthanum-carbonate98653.p2blogs.com/33716744/helping-the-others-realize-the-advantages-of-polishing-powder