A word on India's silver coins and silver billon coins which are an alloy of up to 98% copper and 2% Silver. There is a small number of sellers who misrepresent these coins as being "Silver Bullion" coins when in fact they are as far removed from silver coins as they can be while at the same time retaining there silver color. As for the bright silver luster that the coins present in auction photos there is one more point I want to make. These are antique coins and silver builds up a beautiful patina over the last centuries. The value of these coins is undeniable but you never want to clean them (or any other valuable coin) other than to use a distilled water soak, patience and a soft towel to pat it gently dry. Do not give in to the temptation to scrub your coins, remember, you are just removing the dust or dirt that may have accumulated over the years.
If you ever want to sell your coins and you cleaned them so they present a shiny silver luster, you are in for a disappointing experience. You could have gotten up to ten times what the dealer or collector will offer you for your coins if you had just left them alone. Remember the first rule of ancient coins, if it needs to be cleaned, DON'T DO IT! The second rule is it doesn't matter, if there is a chance that the coin can be valuable, DON'T CLEAN IT!
I collect ancient coins and have been doing so for the last 28 years. I love the beautiful silver billon coins of India's past and the way that each coin can walk you all the way from the beginning of commerce and civilization all the way up to the latest commemorative coins released this year.