Marbles have been valued by collectors for nearly 100 years. Collectors must quickly identify a vintage marble, recognize its manufacturer, spot any flaws and have an in-depth knowledge of the market. Value is only assigned by what another collector pays for a particular piece. Avid collectors regularly study realized prices at vintage marble auctions to maintain a working knowledge of a particular piece's worth.
Identify The Marble Manufacturer
Identify Champion Agate marbles by their trademark swirls. These marbles are often difficult to distinguish from swirled marbles made by other manufacturers. Look for recognizable patterns such as the "Furnace Swirl" and the "Champion Swirl."
Look for a corkscrew pattern when identifying marbles manufactured by Akro Agate. Corkscrew patterns generally have a white base, with a second color twisted into a helix. Other styles and patterns include moonies, oxbloods and corkscrews with three or more colors.
Examine the marble for a logo from a comic strip. These specially licensed marbles were typically manufactured by the Peltier Glass Company, and are prized by collectors. More common marbles made by this company are from their colorful "National Line Rainbo" collection. The various patterns found in this series are usually nicknamed by collectors; various patterns are given names such as a "Zebra" or "Flaming Dragon."
Recognize valuable "Guinea" marbles from the Christensen Agate Company by their brilliant, rare colors and specific pattern. The "Guinea" pattern is a tiger-stripe featuring three or more colors. It is one of the most prized vintage marbles on the collector market.
Identify marbles manufactured before 1950 -- by the Vitro Agate Company -- by their patchwork of colors. Patches-style marbles are generally opaque; they feature three to four colors in a rough, quilt-like pattern.
Determine Estimated Auction Value
Inspect the marble using a jeweler's loupe. Check for pits, cracks, chips or other damage. Evidence of wear or damage reduces the realized price of a marble at auction by over 50 percent.
Check the marble for overall shine. A marble dulled through use or handling has significantly less valuable than one with a bright, glossy finish.
Look for fine bubbles and inclusions; these are signs of a flawed marble or a possible fake. Mass produced and imported cat-eye marbles often have tiny bubbles in the glass; these flaws are evident when viewed through a jeweler's loupe.
Evaluate the marble for its artistic merit. This is a very subjective measurement, because particular qualities of a marble are valued differently by individual collectors. The qualities in most demand are bright, four-color combinations, recognizable shapes within clear glass and marbles that are unusually large or small.
Review auction results and locate marbles with similar qualities. A comparable marble is one of similar size, color and quality, made by the same manufacturer. Marbles typically sell for 50 to 75 percent of the realized auction value when offered in a private sale. Commissions and fees charged by the auction house are responsible for the lowered price.