Objects made of leather are a class apart from any synthetic fiber due to their natural, rich and elegant finish. Today, many similar looking synthetic materials are available in the market sold at a much cheaper price. There are also products that are made only in part with pure leather but are branded as `genuine leather` or `made with genuine leather`. These are ambiguous terms used by marketers to mislead consumers. If you are planning to buy a top quality leather product, which is quite expensive, you must be able to tell genuine leather from synthetic on your own.
Check the surface grain, the little "pebbles" and pores, for imperfections and uniqueness that signal genuine leather. Imperfections, in leather, are actually a good thing. Remember, real leather is made from animal skin, and thus each piece is as random and unique as the animal it came from. Very regular, even, and similar grains often indicate a machine-made piece.
Press into the leather, looking for creases and wrinkles. Real leather will wrinkle under the tough, just like real skin. Synthetic materials usually just depress down under your finger, retaining rigidity and shape
Smell the leather, searching for a natural, musty smell instead of plastic-like or chemical-y. If you're completely unsure of the smell you're looking for, head into a store that you know sells genuine leather and test out a few bags and shoes. Ask if they have any synthetic pieces and smell those as well. Once you know what you're looking for, the smell differences will be unmistakable.
Bend the leather, looking for it to change color slightly in real leather. Similar to the "wrinkle test," real leather has a unique elasticity when bent, changing color and wrinkling up naturally. Faux leather is much more rigid and regular, and will usually be difficult to bend by comparison