Instructions
Examine the porcelain to see if there is the name of a country on the bottom. Generally, the piece will be from around 1890 if there is a country name. During that time, the United States government made it a law that the name appears on porcelain that was imported.
Check the underside of your antique porcelain to see if there are markings such as numbers, letters and marks. Each one has a specific meaning.
Compare any markings of your porcelain to a master list of marks, such as the one found in the book "Kovels Pottery &Porcelain Marks 1850 &Up>" You'll find it at most major bookstores and online at websites such as Collector Book Store (see Resources below). There are also online websites, such as Antique Marks (see Resources below), that help you identify porcelain markings.
Feel the weight of your piece. Older pieces are generally heavier than newer ones because of manufacturing methods.
Look on the bottom for spur marks, which are little bumps. This generally indicates Japanese porcelain from the 1700s to 1800s.
See if a teacup has a handle, as the older ones usually were made without one.