For silver the more important deposits commercially are such compounds as the minerals tetrahedrite and argentite (silver sulfide, Ag 2 S), which is usually associated with other sulfides such as those of lead and copper, as well as several other sulfides, some of which contain antimony as well.
France is the most visited European nation with 83.7 million international tourist arrivals in 2014. Established in the late 1700s, the Louvre Art Museum in Paris is one of the most frequented tourist sites in all of France. Europe is a fascinating continent, and it attracts millions of tourists annually.
Prague seldom visited by tourists until the 1989 is now one of the most popular visited destinations in Europe. Millions of people from all around the world visit the city every year - almost three and a half million in 2004 to 2008.. You must spend at least 3 days to discover Prague city. Berlin isn't much different from Prague. Have Fun