The most common type of crystalline alumina, α-aluminium oxide, is named corundum. When trace elements help it become surface crimson 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 from the Worldwide https://aluminum-oxide43108.madmouseblog.com/15351425/everything-about-diamond-paste