Cobaltoan Smithsonite on Tennantite - image 1

Cobaltoan Smithsonite on Tennantite

This large miniature specimen is a magnificent presentation of the well-known, but rare combination of Smithsonite coating perfect tetrahedral Tennantite crystals known from Tsumeb mine. The Tennantite crystals reach a staggering 3.6 cm on edge and are about as perfect as one could wish for - forming two main large intergrown crystals with other smaller crystals alongside in a shallow plate-like specimen. The Smithsonite presents a pale pinkish colour, indicating that it is slightly cobaltoan, and is extremely well-crystallized but as very small crystals. These crystals form a complete, but relatively thin crust upon the Tennantite and could be described as epimorphous, but the Tennantite is still present underneath rather than as an epimorphic cast. One corner of the second large Tennantite crystal is missing, but its total encapsulation with Smithsonite shows that this is not damage, but a totally natural growth feature. The specimen presents superbly well and the Smithsonite shows absolutely no damage. It really is a perfect example of this classic Tsumeb assemblage and has been hidden for generations within the Weyand collection in Tsumeb. On a technical note, Tennantite is now a subgroup rather than an indvidual species in its own right. We have not analysed this specimen, but it is generally accepted that the majority of Tsumeb specimens are the new species Tennantite-(Zn). This fits perfectly with the outer coating of Smithsonite - a zinc-bearing secondary species.

Unknown Owner

Product details

Species

Smithsonite, Tennantite

SizeSmall Cabinet

Dimensions7.0 x 2.3 x 6.0 cm

Locality

Namibia, Oshikoto Region, Tsumeb

Added on09/06/2025

Comments

Known provenance

2026/01