Tennantite on Pyrite
Posted by: Maia Sinkins on 01.11.2021 | Filed under:

Tennantite on Pyrite

Specimen # 100743
Mineral: Tennantite, Pyrite
Location: Mundo Nuevo Mine, Huamachuco, Sanchez Carrion Province, La Libertad Dept., Peru
Size: 5.6 x 4.6 x 3.8 cm


Detailed Description

This is such a cool specimen – a brilliantly-lustrous pyrite crystal hosts a couple of little “forests” of tennantite crystals. It seems the tennantite crystals chose to grow on the cube faces of the pyrite. The pyrite is incomplete and there is minor chipping visible upon close examination of the tennantites, but this is a great piece – fascinating and totally distinctive.  Stands perfectly for display as photographed.

About these Tennantites

Mundo Nuevo has been best known for its hubnerite, quartz, fluorite and augelite. In recent years there have been occasional excellent finds of tennantite.

These tennantites, mined during 2014-15 specimen recovery work, are part of a find that has now been analyzed quite extensively. Of those (over 40 specimens tested) all were tennantite except one that was a borderline tennantite-tetrahedrite. Accordingly, specimens from this find are now labelled tennantite. I have not had each of these analyzed, given the pervasive tennantite results (and not wanting to add to their prices by incurring unnecessary cost). These tennantites were originally posted on this website labelled “tetrahedrite”, as they were sold to me under that label – they were then removed from the site until the analysis work on the find had been completed.

They are excellent sharp crystals. After the crystals had formed, a late-stage fragmentation and recrystallization event seems to have occurred – the specimens have uneven naturally-fractured surfaces on the back/underside, and these surfaces are recrystallized.


Additional information

Dimensions 70 × 67 × 29 cm