How to Test Depression Glass

Expose your glassware to black light. Green Depression glass glows under black light as a result of the uranium oxide in the glass. Experts do not consider this test foolproof, however, since some newer types of glassware may also fluoresce under black light.

Examine the pattern closely. Most authentic Depression glass pieces are intricately patterned and sharply detailed. If the manufacturer's name appears, it will be sharply etched onto the glassware. Reproduction signatures and patterns will not be as clearly defined. The Cherry Blossom collection of the period, for example, features realistic leaves with veins and saw-toothed edges like real leaves; the cherries appear rounded and lifelike as opposed to flattened.

Do some research to identify authentic shapes and items manufactured during the period. For example, an authentic Depression glass basket-shaped vase will be formed from two parts rather than as a single piece. Vases and tumblers tend to be formed into curved shapes rather than being straight-sided. Some manufacturers introduced a limited amount of pieces in a collection. MacBeth-Evans' original Thistle collection, for example, included only seven original pieces in the set.

Identify genuine colors used during the period. Depression glass was largely available in crystal as well as certain shades of pink, amber, green, blue, yellow and opaque white. Reproductions may have been produced in colors that were not originally manufactured during the Depression era.

Notice the wear pattern. Normal wear will appear as random scratches and dings. Reproductions that are passed off as originals may have been scratched with sandpaper, which will produce more uniform markings.