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. This technology was of major importance to prehistoric cultures before the age of metalworking.

A hammerstone is made of a material such as limestone or quartzite, is often ovoid in shape (to better fit the human hand), and develops telltale battering marks on one or both ends. In archaeological recovery, hammerstones are often found in association with other stone tool artifacts, debitage and/or objects of the hammer such as ore. The modern use of hammerstones is now mostly limited to flintknappers and others who wish to develop a better understanding of how stone tools were made.

Jan Hammer (Czech pronunciation: [ˈjan ˈɦamɛr]) (born 17 April 1948, in Prague, then Czechoslovakia, today the Czech Republic) is a composer, pianist and keyboardist. He first gained his most visible audience while playing keyboards with the Mahavishnu Orchestra in the early 1970s, as well as his film scores for television and film including "Miami Vice Theme" and "Crockett's Theme", from the popular 1980s program, Miami Vice. He continued to work as both a musical performer and producer, expanding to producing film later in his career.

Hammer has collaborated with some of the era's most influential jazz and rock musicians such as Jeff Beck, Al Di Meola, Mick Jagger, Carlos Santana, Stanley Clarke, Neal Schon, Steve Lukather, and Elvin Jones among many others. He has composed and produced at least 14 original motion picture soundtracks, the music for 90 episodes of Miami Vice and 20 episodes of the popular British television series Chancer.

His compositions have won him several Grammy awards.^{[citation needed]}