Marbles are a toy with a very long history. They originated in India as tools for gameplay and were commonly made from stone, glass or clay. Handmade glass marbles were first produced in Germany around 1845. German mass production of marbles began around 1870 with American production following in the 1890s. Inexpensive marbles flooded the markets in the 1950s, and the older handmade marbles gained new popularity as collectors' items. There are several simple ways to determine the age of your marble collection.
Evaluate your marble collection in detail. Most new, mass-produced marbles are distinguished by an inner colored streak resembling a cat's eye -- this is a telltale sign that your marbles are not very old. Old marbles tend to exhibit complex inner streaks (in glass marbles), faded outer markings (in solid colored or clay marbles) and a light weight. For further assistance, you may wish to compare some of your collection to certifiably vintage examples. Visit the link in the "Resources" section for an extensive gallery of old marbles.
Contact the person you have acquired the marbles from. If you have received a collection of old marbles from a relative, ask about the age and history of some of the more unique looking ones. If you purchased them from an auction or online seller, call them or send an email asking for more information about the collection.
Bring your marbles to a local antique shop. Older employees may be able to give you an estimate about the age of your collection in addition to appraisal information. If the shop specializes in vintage toys and games, you're in luck.
Submit detailed pictures of your marbles to an online appraisal service. In addition to telling you the worth of your collection, most services will be able to give you the exact age and original location of production of your marbles. When taking the picture, ensure that the area is well-lit and all of the colors and glass patterns are clear and distinct.