Ask yourself where the item came from. Was it passed down in your family from generation to generation? Then it might be antique--although not always necessarily so. Maybe you found the item in a flea market or estate auction. Antiques are stumbled upon in all these situations but remember, just because an item is old does not mean it is always an antique
Make a small investment in magazines and books about antiques. Publications about identifying antiques are very helpful. They offer advice and information on the latest "popular" fads in antiques and how to tell if something is real or a fake copy. If you'd rather not purchase your own copies, libraries and the Internet offer invaluable free tips and advice about antiques and authenticity of such items
Look for the item's manufacturer. Some items will have an identifying mark used by a manufacturer somewhere on the item. Usually it is on the underside of the piece. If it was produced by a company--it may bear a stamp or indentation--pressed into the item by a piece of machinery or stamping equipment. If it is a handmade piece, for example, a piece of pottery, then it may be hand-signed or have identifying marks such as the creators name, year or sometimes a tiny copyrighting symbol or date.
Research the general decade you think the item came from. For example, Roll top desks, often found to be antiques now, were made in general in the 1940's and 1950's. By researching that time frame you can discover information that could tell you if a particular desk you might own is a valuable original antique or a more recent copy of the real thing.
Be aware that antiques are generally judged by two main criteria, the period of time when made and the materials it was made from. Certain kinds of cloth, wood or glazing techniques were only available in a limited time frame. If you have something that looks old, or even has marks identifying it as antique, it may still only be a copy if it is made out of the wrong material for the decade it is supposedly from. You might still have a collectible item, but it won't be considered an antique.
Valuable antiques or junk? Visit a reputable appraiser. You've done some research in identifying your item but are still not 100 percent sure of the value and authenticity of your item. It is time to visit an appraiser. An experienced appraiser has a highly critical eye and is very experienced at weeding out "fake " antiques. They can tell you if you do indeed possess a valuable antique collectible or just an interesting worthless item. Never underestimate the importance of having your item appraised because some things that people mistake for junk sometimes have been discovered to be rare priceless antiques!