What is lead tetroxide used for? How do I know if my pottery has lead glaze? Why is lead used in ceramic glazes? Why are lead-glazes better than others

Pb₃O₄ 

Lead (II IV) oxide commonly called Red Lead Oxide is an orange or red coloured powder. It is a water-insoluble compound that is prepared by the oxidation of metallic Lead or of litharge (Lead monoxide). It is a useful ingredient for the battery, glass & ceramic industry and it occupies an important place in the paint industry for its rust-inhibiting character. Paint made with Red Lead is commonly used to protect iron and steel from rusting. Red Leads are utilised in a wide range of applications, such as battery manufacture, ceramics, anti-corrosive coatings, crystal glass, and mining.

Lead Tetroxide - Uses in Pottery

Lead tetroxide is most often used as a pigment for primer paints for iron objects. Due to its toxicity, its use is being limited. In the past, it was used in combination with linseed oil as a thick, long-lasting anti-corrosive paint. The combination of minium and linen fibres was also used for plumbing, now replaced with PTFE tape. Currently, it is mostly used for the manufacture of glass, especially lead glass. It finds limited use in some amateur pyrotechnics as a relatively potent oxidizer. Red lead was also used for engineer’s scra­ping, before being supplanted by Engineer’s blue. It is also used for pottery glaze and Enamel. In the electric industry is used to make piezofiles. In the Chemical industry is used as a weak oxidizer.

Formula: Pb₃O₄
Molecular Weight: 685.6 g/mol
Form: Vivid orange crystals
CAS Number: 1314-41-6
Density: 8.3 g/cm³
Synonyms: lead tetroxide, Minium, red lead, triplumbic tetroxide, orange lead, Lead(ii,iv) oxide