The commonest form of crystalline alumina, α-aluminium oxide, is called corundum. When trace things allow it to be appear red it is known as ruby, but all other colorations tumble underneath the designation sapphire. Corundum includes a trigonal Bravais lattice with an area team of R-3c (selection 167 within the https://leonardh294aoz6.newsbloger.com/profile