Metallic crystal aggregates of lillianite, (a Pb-Ag-Bi sulphide mineral), from Municipio de Yecora, Sonora, Mexico. — Photo: David Hospital · CC BY-SA 4.0
Lillianite
Lillianite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Pb₃₋₂ₓAgₓBi₂₊ₓS₆.
It crystallizes in the orthorhombic crystal system (space group Bbmm). It is a member of the Lillianite structural group.
Key properties: Mohs hardness 2–3; specific gravity 7.02–7.16; Black streak; Metallic luster.
IMA symbol Lil, grandfathered status — known before the IMA’s founding, named in 1889.
Found in hydrothermal deposits of probable high-temperature origin.
It is found associated with At a number of early reported occurrences the “lillianite” was shown to be mixtures, especially of galena and galenobismutite; cosalite, cannizzarite.
The name refers to the Lillian mine, Leadville, Colorado, USA, the discredited type locality.