Franckeite - image 1
Franckeite - image 2

Franckeite

Unknown Owner
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This specimen is a very rich, very rare, superb, crystallized specimen of the triclinic lead, tin, iron, antimony sulfosalt Franckeite consisting of somewhat "sword"-shaped crystals oriented into spherical aggregates sitting on matrix. This species belongs to the only group of minerals that forms in naturally "round" or "cylindrical" shaped crystals. This specimen is over 30 years old and was part of the best find of the material. There were only a handful of good specimens, and well crystallized display pieces like this (especially on matrix) are few and far between.

Product details

SpeciesFranckeite
SizeSmall Cabinet
Dimensions6.0 x 5.0 x 3.8 cm
Added on10/23/2024
LocalityBolivia, Potosí, San Jose Mine

Known provenance

DateCollectorAcquisition price
08/2024Unknown OwnerNot disclosed
—The ArkenstoneNot disclosed

Learn more

Mineral guide
Learn about Franckeite
, a rare micaceous lead-tin-antimony sulfosalt, forms layered rosettes and curved plates; Bolivian origin and texture make it collectible.
Franckeite
Regional guide
Franckeite from San José Mine, Bolivia
from the San José Mine is one of the classic Bolivian sulfosalt specimens: black to steel-gray, metallic, soft, heavy, and often built from curving blades and radiating rosettes rather than simple textbook crystals. The best pieces have a lively sheen that moves across the bent plates as the specimen is turned, giving an otherwise dark mineral a surprisingly sculptural presence. Collectors prize San José franckeite because it shows the species in displayable form—not merely as a massive ore constituent, but as rosettes, foliated aggregates, compact sprays, and curved, bladed crystals that express the mineral’s layered structure in the hand.