This square sits on top of a flat surface at sea level on the earth. In this course, we will use some simple rules for finding oxidation numbers from the Periodic Table. Elements in the last column, the halogens, we will take to have the oxidation number -1. Oxygen, we will always assume to have oxidation number -2. Consult a Periodic Table.
Titanium forms an oxide whose mineralic name is perovskite.
It's chemical formulae is CaTiO 3 . It is the principal mineral of limestone rocks. The mineral corundum is an oxide of aluminum. A common family of silicate minerals are called pyroxenes . A good mnemonic is to add silica or SiO 2 to an olivine.