When U.S. troops returned from the Pacific at the end of World War II, they brought home hundreds of thousands of Japanese swords as souvenirs.
Swords worth $50,000 have been found on recreation room walls, so it's important to check out any Japanese sword or dagger.
Start by measuring along the back of the blade. Anything 24 inches or less could be as old as the 1600s and worth $1,000 and up.
If the blade measures 26 or 26.5 inches, you probably have a World War II military-issue sword. If it has a serial number, that makes it worth only a couple hundred dollars, if it's in good condition.
A World War II officer's sword without a serial number can be worth up to $1,000.
But a longer sword, if handmade, could be a genuine samurai sword worth many thousands of dollars, so it's important to get expert advice.
If the handle or scabbard is made of ivory or bone-carved with dragons or flowers, it may be pretty and may even be old. But it's a tourist piece of little value to sword collectors.
Better quality swords are often found in scabbards made of plain wood or highly polished lacquer.
One sword from 1525 was worth $4,000 to $5,000. With a sword like that, you don't even want to touch the blade, because the oils in your hand can damage it.
Whatever sword you have, it's really important that you don't ever clean, polish or sharpen it! It might make the sword look better, but it can slice the value in half.
For more on collectible swords, Hyman recommends long-time collector and appraiser Hank McGonagle at firstname.lastname@example.org.
Find out about other collectibles described by The Saturday Early Show's Tony Hyman in the Collectibles Archive or visit Tony Hyman's Web site.
If you think you have a collectible worth a lot of cash, send an email to email@example.com with "What's It Worth?" in the subject line. Or write to "What's It Worth?" The Saturday Early Show, 514 West 57th St., 6th floor, New York, N.Y. 10019.