An excavation phaser was a specially modified type of phaser used in archaeological endeavors to uncover archaeological evidence. In 2270, a Starfleet Corps of Engineers team examining the asteroid ship Yonada used excavation phasers to uncover an ancient Fabrini mural. The mural had been plastered over, and the team used excavation phasers to break down most of the plaster covering the mural. (TOS novel: Ex Machina)