| IUPAC name
|Appearance||Hard glassy solid or white powder.|
|Density|| 2.460 g/cm3, liquid;|
2.55 g/cm3, trigonal;
|Melting point||450 °C (842 °F; 723 K)|
|Boiling point||1,860 °C (3,380 °F; 2,130 K)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Boron trioxide is a glass like solid or white powder with the chemical formula B2O3.
When produced from boric acid, it forms as a non crystaline mass that is very hard and difficuilt to grind, forming a very fine powder when ground very similar to a solid plane of glass.
It is used in glassmaking, whether as a boron additive for making borosilicate glass or as a fluxing agent so this may be a source, however it is easy to produce from the starting materials boric acid or borax.
Boric acid can be dehydrated above 300 degrees to form boron trioxide. Boron trioxide does not reabsorb this water from the atmosphere so is stable at room temperature.