Silver has long been valued as precious metal. It can be rarely found as nuggets in its native form but is more commonly combined with sulfur, chlorine, antimony and arsenic. The most common silver containing minerals are argentite (Ag2S), chloragyrite (AgCl) and galena (a lead sulfide, PbS, that can contain significant amounts of silver). Silver is primarily produced as a byproduct during the electrolytic refining of copper, lead and zinc. Silver is also produced through the Parkes process, a pyrometallurgical process that takes advantage of the relative solubilities of liquid silver, zinc and lead to recover silver from lead.
Silver is a soft, white, lustrous transition metal. Silver has the highest electrical conductivity, thermal conductivity and reflective properties of any metal. Historically silver has been used in currency, jewellery and silverware and is one of only four precious metals to have a ISO 4217 currency code (XAG). Silver has niche applications in solar panels, water filtration, specialized mirrors, chemical catalysis, medicine and electronics.