Antimony trisulfide
From PyroGuide
Formula: Sb2S3
Synonyms: Stibnite, Antimonite, Antimony sulfide/sulphide, Antimony (III) sulfide/sulphide
Description: Antimony trisulfide is a green powder. It is a fuel used in various white star compositions of the potassium perchlorate-base. It is sometimes used in glitter compositions, fountain compositions and flash powder, however it is used less and less for flash powder as it is very poisonous and can usually be replaced by sulphur or completely omitted. Flash compositions containing antimony trisulfide are very sensitive to friction, shock, and static electricity.
Hazards: Antimony trisulfide should never be used in any mixture containing chlorates, or else spontaneous ignition may occur. Mixtures with antimony trisulfide and perchlorates are very sensitive to friction and shock, and extra caution should be exercised when handling these mixtures. These mixtures are best avoided entirely. Wear proper protective clothing, including a dust mask and gloves, when working with compositions containing antimony trisulfide as it is very poisonous, and toxic to the kindnys and liver. Toxicity: ORAL (LD50): Acute: 7000 mg/kg [Rat] IPR-MUS LD50: 209 mg/kg. Most Antimony trisulphide that has been mined will contain a small Arsenic impurity which can contribute to toxicity depending on levels. At levels above 0.5% the material is classified as hazardous for shipping by air (IATA regulations 2010).
Sources: Antimony trisulfide is sometimes sold as a pigment in (art) paint stores, but it is not commonly found these days due to it's toxicity. It can be made at home by fusing a stoichiometric mixture of antimony metal and sulfur. This is a very dangerous operation since lethally toxic fumes will form, and it should only be performed with proper safety precautions taken.
MSDS:
http://www.hummelcroton.com/msds/ants_m.html