Cylindrite

Cylindrite – FePb3Sn4Sb2S14
Elements: Iron, Lead, Tin, Antimony, Sulfur
Class: Sulfides – Sulfosalts
Crystal System: Triclinic
Hardness: 2.5
Calcite
Talc (1)Diamond (10)
Soft. A fingernail can scratch it.
Origin: Santa Cruz Mine, Poopo Town, Oruro – Bolivia
Did you know?

Cylindrite breaks the rule that crystals have flat faces. A mismatch between its stacked atomic layers forces it to curl up on itself, growing as little metallic tubes and rolls.