Within the Earth, silver is formed from sulfur compounds. In the Earth's crust, the temperature is very hot (approximately 200 to 400 degrees Fahrenheit, depending on how close you are to the planet's mantle). The salt water that exists within the crust concentrates into a brine solution where silver remains dissolved.
Silver is sometimes encountered in pure form. It also is mined from the minerals acanthite (silver sulfide) and stephanite. Silver also is found in the common minerals chlorargyrite (silver chloride) and polybasite. Silver is mined in many countries, but most comes from the USA, Canada, Mexico, Peru and Bolivia.
Silver is found in lead, zinc, gold, and copper ore deposits. The most important ore mineral of silver is argentite (Ag2S, silver sulfide). Silver is commonly extracted from ore by smelting or chemical leaching.