Appearance
Arsenic is a steel grey, brittle, crystalline metalloid.

Source
The commonest Arsenic containing mineral is Mispickel, and others including Realgar and Orpiment. Arsenic can also be found in the native state. It can be obtained from Mispickel by heating, which causes the Arsenic to sublime and leaves the Iron (II) sulphide.

Uses
Arsenic is used in bronzing, pyrotechny and for hardening shot. It is increasingly being used as a doping agent in solid state devices.

General Information
Arsenic has several allotropes. The most common is grey Arsenic, which tarnishes and burns in Oxygen. It resists attack by acids, alkalis and water but it is attacked by hot acids and molten Sodium hydroxide. When heated, it sublimes.

Arsenic is toxic in small doses and is also a suspected carcinogen. Calcium and Lead Arsenic compounds are used as agricultural poisons.