When it comes to purchasing Silver, one factor to consider is purity. The purest form of silver available on the market is .9999 fine silver. The Royal Canadian Mint produces their popular Silver Maple Leaf series in .9999 fine Silver.
This highest level of purity is more expensive and time-consuming to create, making it more uncommon than the other .9999 and .999 fine Silver items produced by sovereign and private mints. Your typical silver bullion product is .999 fine and meets the needs for most stackers or investors.
By contrast, gold can be up to .99999 fine. Again, the Royal Canadian Mint produces some amazing gold commemoratives with .99999 fine gold.