Antimony pentasulfide, with the chemical formula Sb2S5, is a chemical compound composed of two antimony ions (Sb3+) and five sulfide ions (S2-). It is a dark gray or black crystalline solid and occurs naturally as the mineral known as stibnite pentasulfide.

Antimony pentasulfide has several key properties and uses, including:

1. Pigment: It is used as a black pigment in certain applications, such as in paints, inks, and dyes.
2. Pyrotechnics: Antimony pentasulfide is used in pyrotechnic compositions to produce specific effects, such as glitter and sparkle.
3. Matches: Historically, stibnite (antimony pentasulfide) was used in the manufacture of friction matches, where it served as a component of the match head.
4. Traditional Medicine: Like stibnite (antimony trisulfide), antimony pentasulfide was used in traditional medicine for various purposes. However, its use in medicine has declined due to its toxicity.

It’s important to note that antimony compounds, including antimony pentasulfide, contain antimony, which is known to be toxic to humans and can cause health effects if not handled properly. Therefore, it is essential to use appropriate safety measures, including using personal protective equipment, when working with antimony compounds or any antimony-containing materials.

As a pigment and a source of antimony for various applications, antimony pentasulfide has been used historically in traditional medicine, matches, and pyrotechnics. However, due to safety concerns and the availability of safer alternatives, its use in some of these applications has diminished over time.