Mahogany furniture can be solid hardwood or plywood veneer. Plywood veneer is often used as a cheaper alternative to solid hardwood. If adequately finished, plywood veneered furniture will last almost as long as traditional hardwood furniture. There are pros and cons between each product, with either one coming out on top depending on the applications of the furniture. Plywood veneer and solid mahogany both have common uses in furniture building.
Look at the furniture's legs. If they are round, have round spindles, carvings, scallops, flutes or any other aesthetic features, they are solid mahogany lumber. If the legs are square, over 4 inches wide and the grain pattern is very similar on all four sides, it's veneer.
Look at the side of table tops on mahogany end tables, kitchen tables or coffee tables. Veneered plywood will have a grain pattern on the edge of the table top that runs horizontally. Solid mahogany table tops will have no grain on the edges. The edges will look almost black with tiny holes; these are the pores in the wood. The sides of solid mahogany will also show vertical splices where separate pieces of lumber are glued together.
Pick up the furniture. Compare the weight to a similar piece of furniture. If it's mahogany veneer, the furniture will appear to be extremely lightweight -- far lighter in weight than you would expect.
Look for color variations. Solid mahogany will have subtle color variations throughout the furniture. You will see dark streaks, darker pieces on the ends of moldings or legs. The color will range from a light-red to an almost orange-red to white streaks of light-amber color. Mahogany veneer will look very consistent, almost benign and lifeless with almost no color variations whatsoever.
Apply a general rule of thumb. If the cost of the mahogany furniture is affordable and comparative to what you might find in a department store, it's probably veneered plywood. If the cost of the furniture seems almost extravagant, and it is featured in the high-end furniture stores, the piece is probably solid mahogany.
Don't be afraid to buy veneered mahogany. In some instances, it can be superior to solid mahogany such as on table tops. Solid mahogany is prone to warping and cracking while mahogany veneered plywood is not.