This meteorite was recognized in 1850, although it was known before that time.
The earliest account of the meteorites is by a Sonoran official, Jose Francisco Velasco, who says several iron masses were found between Tucson and Tubac, in Puerto de los Muchachos (mountain pass of the children) and at the foot of Sierra de la Madera (mountain range of timber). One mass, he said, was taken to the Tucson presidio.
The Tucson meteorite consists of two known masses. One is called the Signet (688 kg), because it is ring-shaped. The other is called the Carleton Iron (287 kg), because it was confiscated by Colonel Carleton during the Civil War and sent to San Francisco. Both masses were used as anvils in presidio blacksmith shops. Both masses are now currated by the Smithsonian Institution. The Signet (sometimes called the Tucson Ring Meteorite) is one of the most photographed and treasured iron meteorites because of its unusual shape.