Silver is a soft metal, and when used in teapots and services, it is mixed with copper to form a harder, more durable alloy. The small amount of copper used in sterling silver pieces does not detract from its value as a silver teapot. Detraction only happens if the percentage of copper is too high, or if the teapot is being bought or sold as sterling silver when it is actually German silver or silver plated. Knowing the percentage of silver in your teapot gives you the true value of your silver piece.
Study the bottom of the teapot. Look for any letters, numbers or pictures that are stamped into the metal. Numbers may indicate the amount of silver while letters may indicate that the piece is sterling silver or German silver. Pictures are often found on European silver and tell the piece's origin, maker and year of production. Marks can also identify the piece as a fake, so it is important to know what these marks mean.
Determine the actual percentage of silver by noting any numbers. A teapot stamped with .925 or 9.25 contains the highest available percentage of silver. Out of 1,000 parts of pure silver, there are only 75 parts of copper.
Identify words or abbreviations stamped in the silver. Finding an S/S stamp means you are in possession of a true sterling silver piece. If this mark stands alone, you can be assured that your silver is .925 per cent pure.
Look for hallmarks. A hallmark is a symbol used by European silversmiths and is usually stamped into pieces in a series that denotes the town, maker and year of creation. Pure British silver will bear the standing lion stamp, known as the "Lion Passant." Scottish silver, which bears a thistle stamp, is very rare.
In the absence of any marks on the teapot, try sticking a magnet to it. Sterling is not magnetic. If the magnet sticks, you likely own a plated piece. Take your teapot to a jeweller or antique dealer to have it appraised.
Do not be fooled by teapots containing "G/S", "EPBM," "EPWM," "EPNS" or "EPC." The first abbreviation is for German silver which contains no silver at all but is instead an alloy made up of various non-precious metals. The latter four indicate silver plate or electroplating that has little real value.