Mineral Class 04: Oxides and hydroxides

Cassiterite crystals on a dark violet fluorite matrix from Solnechnoe Sn deposit (Solnechny), far-eastern region, Rusland
The oxide mineral class includes those minerals in which the oxide anion (O2) is bonded to one or more metal ions.
The hydroxide bearing minerals are typically included in the oxide class.
The minerals with complex anion groups such as the silicates, sulfates, carbonates and phosphates are classed separately.