A classic locality that once produced outstanding Bournonite crystals is the Herodsfoot Mine, Lanreath, Liskeard District, Cornwall, England. The old type locality
for Bournonite is also in Cornwall at Wheal Boys, Port Isaac. Excellent crystal clusters of thick crystals have come from France at the Les Malines District, Saint-Laurent-le-Minier, Gard. Fine Bournonite has also come from the Georg Mine, Willroth, Altenkirchen, Rhineland-Palatinate, Germany; and from Příbram, Bohemia, Czech Republic. Several of the Transylvanian ore
mines in Maramureș Co., Romania have produced good forms of this mineral, especially Baia Sprie and Cavnic (Kapnik), where the Bournonite occurs in dense crystal clusters.
A relatively recent find of exceptionally large and lustrous Bournonite crystals is the Yaogangxian Mine, Yizhang, Hunan Province, China. This locality has set a new standard for this species, with some of the largest and most lustrous crystals ever found. Nice crystal groups have come from the Chichibu Mine, Nakatsugawa, Saitama Prefecture, Japan.
Excellent Bournonite crystals, often tabular
with a squared shape, are well known from the Machacamarca District, Potosí Department, Bolivia. Several of the silver ore deposits in Peru have produced fine crystal clusters, especially the Quiruvilca Mine, La Libertad Department; the Pachapaqui District, Ancash Department; the Casapalca Mine, Lima Department; and Cerro de Pasco, Pasco Department. In Mexico, good Bournonite crystals have come from the Noche Buena Mine, Mazapil, Zacatecas; Conception del Oro, Zacatecas; and Naica, Chihuahua. Good Bournonite is very rare in the U.S, where its most prominent locality is the Silver King Mine, Park City, Summit Co., Utah.