THE BASIC PRINCIPLES OF DIAMOND WHEEL

The commonest kind of crystalline alumina, α-aluminium oxide, is named corundum. When trace things help it become appear crimson it is referred to as ruby, but all other colorations tumble under the designation sapphire. Corundum includes a trigonal Bravais lattice with an area team of R-3c (quantity 167 during the International Tables).) that app