Junk silver is an informal term used in the United States, United Kingdom, Canada and Australia for any silver coin which is in fair condition and has no numismatic or collectible value above the bullion value of the silver it contains. Such coins are popular among people seeking to invest in silver, particularly in small amounts. The word "junk" refers only to the value of the coins as collectibles and not to the actual condition of the coins; junk silver is not necessarily scrap silver.

Precious metals including silver are measured in troy ounces (ozt). A spot price for silver is the price for a troy ounce of silver which is 99.9% pure, or 999 fine. Silver coins including junk-silver coins have set silver-alloy contents ranging from 35% to 90% or more. The term "coin silver," for example, refers to 90-percent silver alloy which was the most common alloy used to mint silver U.S. coins.

Any combination of 80% silver Canadian coins which have a face value of $1.00 contains about 0.6 troy ounces of 99.9% silver.  Ten and 25 Cent coins of 1967 and 1968 contain less silver.

Any combination of 90% silver U.S. coins which have a face value of US$1.00 contains 0.7 troy ounces of 99.9% silver, except for the silver dollars (Morgan and Peace) which contain .7736 troy ounces of silver. In other words, a full troy ounce of 99.9% silver is contained in any combination of 90% silver U.S. coins which have a face value of US$1.40.

Junk silver coins are sold at spot price, making for a great way to invest in affordable, incremental quantities of silver.