What are the two principal commercial oxides of arsenic?

The two principal commercial oxides of arsenic are:

• Arsenious oxide (As₄O₆), also commonly known as white arsenic. It is obtained as a by-product from the roasting of various metal ores and serves as the primary starting material for most other arsenic compounds. It is utilized in pesticides, as a glass decolorizer, and as a hide preservative.1
• Arsenic pentoxide (As₂O₅), which is produced by the action of an oxidizing agent, such as nitric acid, on arsenious oxide. It is a major ingredient in the manufacture of herbicides, insecticides, and metal adhesives.1

These compounds are the most important commercial forms of arsenic oxides.12