No. The only Australian decimal coin to ever contain any silver, was the 1966 round 50 cent coin. They were withdrawn from circulation when the price of silver skyrocketed in 1967.
Silver had become far too expensive to make general circulation coins from and a cheaper method was to use an alloy of copper and nickel. This was an international trend during the mid to late 20th century. The last ever Australian circulating coin to contain any silver was the round 1966 50 cent coin which had a silver content of 80%. This coin was withdrawn in 1967 due to the sky rocketing price of silver. From 1946 to 1964, all Australian predecimal "silver" coins had a 50% silver content. From 1910 to 1945, all Australian predecimal "silver" coins had a 92.5% silver content.
The government stopped putting solid silver coins out in the late 60's. Any 50 cent piece past 1969 will not be silver.
You can as a federal reserve note but not in silver coin. The US government in the late 1960s halted redemption of silver coin for silver certificates.
All US silver coins minted for circulation since the late 1830s have consisted of 90% silver and 10% copper except for the Jefferson War Nickel which contained 35% silver.
Sterling silver also became a popular material during the late 1960s and early 1970s.
Silver was effectively removed from U.S. currency in 1965 when the Coinage Act eliminated silver from dimes and quarters, replacing it with a copper-nickel blend. While silver had been used in coins for centuries, this act marked a significant shift in U.S. monetary policy. The last circulating silver dollar was produced in 1935, and by the late 1960s, silver was no longer used in regular coinage.
That is an INCREDIBLY broad question!! U.S. silver coins were struck in 5 denominations and at 5 mints from the 1790s to the 1960s so there are thousands of possibilities to choose from. As a rule of thumb most silver coins from the late 1940s to 1964 are worth most for their metal content, about $3 for a quarter, $6 for a half, etc. However other older coins may be worth only that much or may be worth considerably more depending on their date and where they were made. You can go to a site such as www.Numismedia.com that lists values for all U.S. coins to get an idea of current retail prices.
Strictly speaking, no coin is pure silver. The refining process can't produce 100% silver, although high-end techniques can come within 0.1%. That level of purity is only available in special bullion coins sold to collectors and investors. These items almost always have their purity level ("fineness") either on the coin's packaging or struck into the design itself. Examples are the "silver eagle" coins issued by the US, panda coins from China, and Australian "koala" pieces. Nearly-pure silver is too soft to be used in circulating coins. They'd wear out very quickly, so in the past when various countries minted silver coins the metal was always alloyed with copper or some other base metal to harden them. Britain used .925 file (92.5% pure) silver in some coins prior to 1920. The US used .900 (90%) silver up till 1964, while Canada used .800 silver till 1967 and .500 for a while after that. However once silver prices were completely deregulated in the late 1960s countries worldwide switched to non-precious metals like cupronickel, steel, and so on.
Most likely not. You did not specify a country of origin, but most countries completely ended circulating silver coinage by the late 1960s with a few exceptions of coins with very high face values.
Of course. And "coin silver" only refers to the US standard of 90% pure silver coins. Most other countries (especially in the British empire) used to use sterling silver. Coins have used many different alloys, for example, post WWI Canadian coins are 80% silver, silver UK coins dated 1920-1946 are 50% silver, some ancient "silver" coins are known as billion coins and they contain very little silver, and Mexico issued a 1 peso coin in the late 1950s and 60s that was only 10% silver!
The Romans had a number of silver coins: the denarius, the sestertius and the argenteus. In the Late Empire there were the miliarense and the siliqua. The Romans also had gold, bronze, brass and copper coins.
Silver dollars intended for circulation were made from the start of the US mint in the late 1700s all the way to 1935. However, the silver dollar has always been an unpopular coin when silver was in our circulating coins. Silver dollars were in circulation to where an average person could pick one up at the bank (or cash in silver certificates for silver dollars) up until the increase in silver prices in the mid-1960s. Soon after that, the price of the silver increased over their face value and they went to collectors.