3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||235.644 g/mol|
|Density||3.77 g/cm3 |
|Melting point||1,090 °C (1,990 °F; 1,360 K)|
|365 g/100 ml|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
There are four polymorphs, α (hexagonal), α' (monoclinic), β(hexagonal) and γ(cubic). The alpha form is yellow. The crystal structures are related to those of ZnS with gallium in tetrahedral positions. The alpha and beta forms are isostructural with their aluminium analogues. The similarity in crystal form of gamma- with sphalerite (zinc blende), ZnS is believed to explain the enrichment of gallium in sphalerite ores.
The method of production can determine the polymorphic form produced, the reaction of Ga(OH)3 with H2S at different temperatures is reported to produce a different polymorph depending on the temperature, α- 1020 K, β- 820 K and γ- above 873 K 
Ternary sulfides MIGaS2, MIIGa2S4 and MIIIGaS3 respectively have been of interest due to their unusual electrical properties and some of these can be prepared by reactions of Ga2S3 with metal sulfides e.g. CdGa2S4:-
Although by itself Ga2S3 is not a glass former it can be reacted with rare earth sulfides to form glasses e.g. the reaction with lanthanum sulfide, La2S3, forms gallium lanthanum sulfide glass which has interesting optical properties and is a semiconductor.