In chemistry, the term stannate or tinnate refers to compounds of tin (Sn). Stannic acid (Sn(OH)₄), the formal precursor to stannates, does not exist and is actually a hydrate of SnO₂.^[1] The term is also used in naming conventions as a suffix; for example the hexachlorostannate ion is SnCl²⁻
₆.

In materials science, two kinds of tin oxyanions are distinguished:

• orthostannates contain discrete SnO⁴⁻
  ₄ units (e.g. K₄SnO₄) or have a spinel structure (e.g. Mg₂SnO₄)
• metastannates with a stoichiometry M^IISnO₃, M^I
  ₂SnO₃ which may contain polymeric anions or may be sometimes better described as mixed oxides

These materials are semiconductors.^[2]

Examples

• Barium stannate, BaSnO₃ (a metastannate)
• Cobalt stannate, Co₂SnO₄, primary constituent of the pigment cerulean blue
• Dysprosium stannate, Dy₂Sn₂O₇
• Lead stannate, Pb₂SnO₄, "Type I" lead-tin yellow
• Potassium stannate, formally potassium hexahydroxostannate(IV), formula K₂Sn(OH)₆
• Sodium stannate, formally sodium hexahydroxostannate(IV), formula Na₂Sn(OH)₆