This small charm, intended to suspend from a souvenir bracelet from the late 19th-early 20th Century.
The main armory building is at center in this piece of souvenir jewelry from Springfield Armory, Springfield, Massachusetts. It has no markings on the reverse, nor pin, but simply intended to hang from a souvenir bracelet from someone’s travels from the late eighteen hundreds to the early 20th Century.
Engraved in the lower banner, “U.S. Armory.”
It measures 20mm high and wide, approximately. I am assuming it to be silver, or a good silver plate.