Damascus steel does not refer to one particular type of steel. Damascus steel is formed of layers of different steel types that are forge welded together to create the blade. Treating the polished Damascus blade with acid, otherwise known as etching, reveals the pattern formed from the different steel layers. The acid treatment darkens the different steel layers to varying degrees. There can be an infinite number of patterns and steel compositions.
The beauty and the quality of the piece depend mostly on the steel used and the expertise of the forge welding. The Damascus pattern is determined by the forging techniques and can be replicated in many blades. There are many specific patterns such as Wild, Raindrop, Turkish, Ladder, Mosaic, and many others. The patterns can be extremely intricate and beautiful.
Damascus steel is a good material for a sword. It can withstand multiple hits on armor. The cutting ability of the sword depends on the steel type that is exposed at the cutting edge. Because Damascus blades are composed from many steels welded together, the general toughness of the blade is a result of the quality of the welding. Some examples of Damascus steel demonstrate outstanding quality, but Damascus steel was originally developed as a cheaper substitute for Wootz steel.