Silver is more than just your earring, or your grandmothers special occasion dinnerware...
Silver has the symbol Ag and atomic number 47 on the periodic table, and is a soft and lustrous transition metal. The name has several possible origins, including the Old Norse "silfr", and the symbol Ag comes from the Latin word for silver, argentum. Its position on the periodic table is what gives it most of its unique qualities; it has the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. It’s also a relatively weak metal, making it useful for some applications and less so for others. It is actually so pliable that it can be drawn into a wire one single atom thick!!
It can be found in the Earth’s crust (the top layer of the earth) in the free elemental form called “native silver”, which is likely why it has been used for millennia in human culture. Silver’s usefulness is sometimes offset by its cost, so typically either alloys (mixtures) are made or substitutions are found.
Sterling Silver is an alloy of silver containing 92.5% Silver and 7.5% a secondary element, usually Copper. The sterling alloy originated in continental Europe and was being used for commerce as early as the 12th century in Northern Germany, and really widened in use during Colonial America. In fact Paul Revere was a master silversmith!
Silver is not very reactive chemically, which may sound contradictory given that I've written a whole page on how to clean tarnished silver...but essentially the issue isn't the water or the air...it's all the pollution! That is what causes the oxidation (blackening) that you see over time.
So, long story short...wear your silver in outer space and it’ll last forever.