The Stone Age is a broad prehistoric time period during which humans widely used stone for toolmaking.
Stone tools were made from a variety of different kinds of stone. For example, flint and chert were shaped (or chipped) for use as cutting tools and weapons, while basalt and sandstone were used for ground stone tools, such as quern-stones. Wood, bone, shell, antler(deer) and other materials were widely used, as well. During the most recent part of the period, sediments (like clay) were used to make pottery. A series of metal technology innovations characterize the later Chalcolithic (Copper Age), Bronze Age and Iron Age.


Obsidian projectile point
The period encompasses the first widespread use of technology in human evolution and the spread of humanity from the savannas of East Africa to the rest of the world. It ends with the development of agriculture, the domestication of certain animals and the smelting of copper ore to produce metal. It is termed prehistoric, since humanity had not yet started writing -- the traditional start of history (i.e., recorded history).
The term "Stone Age" was used by archaeologists to designate this vast pre-metallurgic period whose stone tools survived far more widely than tools made from other (softer) materials. It is the first age in the three-age system. A division of the Stone Age into an older and younger part was first proposed by Jens Jacob Worsaae in 1859 through his work with Danish kitchen middens that began in 1851.[1] The subdivision into the Palaeolithic, Mesolithic and Neolithic periods that still is in use today, was made by John Lubbock in his now classic 1865 book Pre-historic Times. These three periods are further subdivided. In reality, the succession of phases differs enormously from one region (and culture) to another, indeed, humanity continued to expand into new areas even during the metal ages. Therefore, it is better to speak of a Stone Age, instead of the Stone Age. As a description of people living today, the term stone age is controversial. The Association of Social Anthropologists discourages this use.