To identify the value of antique bone china, use marks on the china to find out where, when and by what manufacturer it was made. Knowing the pattern is also important, as it contributes greatly to the value. Once you gather all the information, look at different auction websites, find a similar piece that was already sold there and use its price as an estimate. You may also find the price on the manufacturer's website.
To find the manufacturer's hallmark, look at the bottom of a dinner plate, a saucer or the sculpted item, and find a mark that should be located in the center. It may look like a picture, a combination of numbers, letters or a word, which identifies the manufacturer or the country of origin. The hallmark might be painted or printed onto the material, impressed in it. Find a similar mark on china in porcelain and pottery books or online.
To find out the name of the pattern on the china, find a three- or four-digit number somewhere near the hallmark. The number should correspond to the name of the pattern. Use manufacturer's and collector's websites that have lists of these numbers to find out the pattern's name.
If you weren't able to find the value of the piece online, talk to local antique collectors and appraisers, and have them estimate the value.