In the past Americas coins were made mostly of precious metals. Some used gold and some silver however either precious metal was usually mixed with base metals to enhance durability since they were expected to change hands many times in the course of commerce. In a day when we don't use any precious metals based currency on a daily basis this must seem like a strange and distant time. It really was not that long ago however that Americans completed transactions using silver coinage on a regular basis. The early 1960s saw the change from precious metals based silver quarters to the copper and nickel variants we use today.
The Original Quarter
The original quarter was loosely based on the very popular Spanish dollar of the time which was regarded as the world standard in silver coinage and accepted by merchants and traders the world over. As depicted in pirate literature and films, the Spanish dollar was often divided into sections of eight for transactions not requiring the full value of a dollar and two of the bits equalled one quarter of a dollar. In 1792 the US Mint came into existence via the Coinage Act but the Spanish silver dollar remained popular for a long time after that point.
Silver Quarters Today
Today the value of silver quarters (the ones left over from production up until 1964) is based primarily on their silver content which individually is quite small but when combined and multiplied by the current price of silver can give you a very significant figure.
The most recent silver quarter produced was the Washington style which looks essentially like the quarters we've used for the past 40-50 years but was made of 5.625 grams of silver and 0.625 grams of copper. This put the silver content at 90% of the coin's gram weight. With a little calculation we see that at the current silver prices of just over forty dollars per ounce the current value of Washington silver quarters is about $7.28.
These types of quarters are a good way to get into using silver as an alternate form of savings in an environment of heightened inflation. It is not always the case but at times you can get old silver quarters at a minimal premium over the silver contract spot price compared to other more attractive and easy-to-deal-with form of silver like bullion bars or rounds. There isn't anything wrong with junk silver coins that makes this the case they are just somewhat less convenient although with rising silver prices it will take fewer of them to amount to a large dollar figure.