(TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
| USA | | |
| US Bureau Mines glossary | |
| Gordon\'s Mineralogy of Pennsylvania (1922) p. 191 | |
| Gordon, \"Mineralogy of Pennsylvania\" 1922 p. 193. |
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