is Iron Lead Antimony Sulfide with formula FePb3Sn4Sb2S14 and hardness of 2.5.
A unique type of mineral formed in cylindrical crystal grouped like a brushwood. Actually are coiled sheets that looks like they have been rolled into tubes.
This strange material comes from one location only in the world: the Mina Santa Cruz,Poopo ,Oruro,Bolivia and few other tin sulfide deposit.
Never facet before, a really unusual stone for collectors.
Some natural cavities may be present on the surface.