How do I identify Senarmontite?

Senarmontite can be identified by its hardness of 2 - 2.5 on the Mohs scale, Colourless to gray color. Look for these key characteristics when examining specimens.

What color is Senarmontite?

Senarmontite typically appears in Colourless to gray. Color can vary depending on impurities and formation conditions.

How hard is Senarmontite?

Senarmontite has a hardness of 2 - 2.5 on the Mohs scale. This makes it a soft mineral that can be scratched easily.

Senarmontite

A variety of Minerals

What is Senarmontite?

Antimony(III) oxide is the inorganic compound with the formula Sb2O3. It is the most important commercial compound of antimony. It is found in nature as the minerals valentinite and senarmontite. Like most polymeric oxides, Sb2O3 dissolves in aqueous solutions with hydrolysis. A mixed arsenic-antimony oxide occurs in the nature as the very rare mineral stibioclaudetite.

Uses & Applications

The annual consumption of antimony(III) oxide in the United States and Europe is approximately 10,000 and 25,000 tonnes, respectively. The main application is as flame retardant synergist in combination with halogenated materials. The combination of the halides and the antimony is key to the flame-retardant action for polymers, helping to form less flammable chars. Such flame retardants are found in electrical apparatuses, textiles, leather, and coatings. Other applications: Antimony(III) oxide is an opacifying agent for glasses, ceramics and enamels. Some specialty pigments contain antimony. Antimony(III) oxide is a useful catalyst in the production of polyethylene terephthalate (PET plastic) and the vulcanization of rubber.

Senarmontite Market Value Calculator

Estimate the market value of Senarmontite using size, quality, and finish. This preview calculator is for quick context and is not a formal appraisal.

Senarmontite Localities Map

See where Senarmontite is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.

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North ZoneCentral RidgeSouth Basin

Key Characteristics

Characteristics of Senarmontite

Antimony(III) oxide is an amphoteric oxide, it dissolves in aqueous sodium hydroxide solution to give the meta-antimonite NaSbO2, which can be isolated as the trihydrate. Antimony(III) oxide also dissolves in concentrated mineral acids to give the corresponding salts, which hydrolyzes upon dilution with water. With nitric acid, the trioxide is oxidized to antimony(V) oxide. When heated with carbon, the oxide is reduced to antimony metal. With other reducing agents such as sodium borohydride or lithium aluminium hydride, the unstable and very toxic gas stibine is produced. When heated with potassium bitartrate, a complex salt potassium antimony tartrate, KSb(OH)2•C4H2O6 is formed.

Composition of Senarmontite

The structure of Sb2O3 depends on the temperature of the sample. Dimeric Sb4O6 is the high temperature (1560 °C) gas. Sb4O6 molecules are bicyclic cages, similar to the related oxide of phosphorus(III), phosphorus trioxide. The cage structure is retained in a solid that crystallizes in a cubic habit. The Sb-O distance is 197.7 pm and the O-Sb-O angle of 95.6°. This form exists in nature as the mineral senarmontite. Above 606 °C, the more stable form is orthorhombic, consisting of pairs of -Sb-O-Sb-O- chains that are linked by oxide bridges between the Sb centers. This form exists in nature as the mineral valentinite.