Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: May 1, 2005
Publication Date: January 1, 2006
Citation: Nielsen, F.H. 2006. Arsenic. In: Klasing, K.C., editor. Mineral Tolerance of Animals. 2nd Revised Edition. Washington DC; National Academies Press. p. 31-41. Technical Abstract: Arsenic is a solid, brittle metalloid and thus has both metallic and nonmetallic properties. The most common stable form of arsenic at room temperature is metallic or gray arsenic. Another form of elemental arsenic, yellow arsenic, occurs when arsenic vapors are cooled suddenly to below 0o C (Stoeppler, 2004). It is unstable and more volatile than gray arsenic. Arsenic is the 20th most common element in the earth's crust with an average natural abundance of about 1.5-3 mg/kg (Mandal and Suzuki, 2002). Arsenic naturally occurs in over 200 different forms with approximately 60% as arsenates, 20% as sulfides and sulfosalts, and the remainder as arsenides, arsenites, oxides, silicates and the elemental form (Mandal and Suzuki, 2002). The most common arsenic mineral is arsenopyrite. Other common minerals of arsenic are orpiment and realgar (natural sulfides) and arsenolite. However, arsenic in its most recoverable form is found in various types of metalliferous minerals (Mandal and Suzuki, 2002) such as iron pyrite, galena, chalcopyrite and sphalerite. Arsenic trioxide, the common commercial form of arsenic, is produced as a byproduct of roasting various ores.