In archaeology

Archaeology

Archaeology, or archeology , is the study of human society, primarily through the recovery and analysis of the material culture and environmental data that they have left behind, which includes artifacts, architecture, biofacts and cultural landscapes...

 a blade is a type of stone tool

Stone tool

A stone tool is, in the most general sense, any tool made either partially or entirely out of stone. Although stone tool-dependent societies and cultures still exist today, most stone tools are associated with prehistoric, particularly Stone Age cultures that have become extinct...

 created by striking a long narrow flake

Lithic flake

In archaeology, a lithic flake is a "portion of rock removed from an objective piece by percussion or pressure," and may also be referred to as a chip or spall, or collectively as debitage. The objective piece, or the rock being reduced by the removal of flakes, is known as a core. Once the proper...

 from a stone core

Lithic core

In archaeology, a lithic core is a distinctive artifact that results from the practice of lithic reduction. In this sense, a core is the scarred nucleus resulting from the detachment of one or more flakes from a lump of source material or tool stone, usually by using a hard hammer percussor such...

.

Blades are defined as being flakes that are at least twice as long as they are wide and that have parallel or subparallel sides and at least two ridges on the dorsal (outer) side. Additionally, a tool must be part of an intentional blade industry in order to properly be considered a blade; tools which show the characteristics of blades through variation but are not intentionally produced with those characteristics are not considered true blades. Blades became the favoured technology of the Upper Palaeolithic era, although they are occasionally found in earlier periods. A soft punch or hammerstone

Hammerstone

In archaeology, a hammerstone is a hard cobble used to strike off lithic flakes from a lump of tool stone during the process of lithic reduction. The hammerstone is a rather universal stone tool which appeared early in most regions of the world including Europe, India and North America...

 is necessary in creating a blade and their long sharp edges made them useful for a variety of purposes. They were often worked to create scraper

Scraper (archaeology)

In archaeology, scrapers are unifacial tools that were used either for hideworking or woodworking purposes. Whereas this term is often used for any unifacially flaked stone tool that defies classification, most lithic analysts maintain that the only true scrapers are defined on the base of...

s or burin

Burin

Burin from the French burin meaning "cold chisel" has two specialised meanings for types of tools in English, one meaning a steel cutting tool which is the essential tool of engraving, and the other, in archaeology, meaning a special type of lithic flake with a chisel-like edge which was probably...

s.

Cores from which blades have been struck are called blade cores and the tools created from single blades are called blade tools. Small examples (under 12 mm) are called microblades and were used in the Mesolithic

Mesolithic

The Mesolithic is an archaeological concept used to refer to certain groups of archaeological cultures defined as falling between the Paleolithic and the Neolithic....

 as elements of composite tools. Blades with one edge blunted by removal of tiny flakes are called backed blade.