short definition: toxic element often present in copper ores
a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but only the gray form, which has a metallic appearance, is important to industry.
acronym: As
note: In some cases, As acts as a byproduct of copper mining. But mostly, As is a deleterious element in copper ore and subsequently in copper concentrate that results in penalties for miners in copper processing by smelters. Sometimes, arsenic acts as an alloying element for copper.