During what time period was a silver quarter with an eagle in flight made?
You are referring to Standing Liberty Quarters, which were minted from 1916 to 1930.
It depends on the quarter. From 1932-1964 silver quarters had the familiar Washington eagle design on the back, just like clad quarters up until the state quarter series. The Standing Liberty quarters depict an Eagle in flight, the barber quarter has a heraldic eagle on the reverse and earlier coins usually have something stating that it is a quarter of a dollar.
Generally yes, very much so. Silver has fluctuated in value but has been in the $10 to $18 range during most of the period 2006-2008, so that makes a silver quarter worth at least 5 or 6 times its face value. Also, silver quarters are older so some of them are scarce enough to be worth even more as collector's items.
Not at all! Silver certificates were redeemable at banks for silver metal in an amount equal to their denomination. The smallest silver certificate has a denomination of $1 so it was equal to 4 quarters. During the 20th century, there were also $5 and $10 silver certificates and during the 19th century silver certificates were printed in every denomination from $1 to $1000.
You don't have a pure silver quarter as the US has never minted a pure silver (99.9% pure or higher) silver quarter. Instead what you have is a 90% silver quarter which would be dated 1964 or prior. The value depends on a number of factors including the date, the mintmark and the condition. But a silver quarter is worth $5-6 in scrap silver regardless of type or condition, however some quarters can be worth…
No, clad is used in the coin collecting community talking about the Copper and Nickel "sandwich" current, non-silver, coins have. So a clad quarter by definition would not have any silver because a clad quarter is a quarter with no silver. However, quarters were made of silver before 1965 so any quarter dated 1964 and earlier contains 90% silver, but those coins would not be considered "clad".