Sphalerite (Zinc Ore)

This container holds three representative specimens of sphalerite, collected from the historic Johnston’s United Mine near Rockville, Tasman. Sphalerite is the principal ore of zinc and is commonly found in hydrothermal vein systems associated with lead, silver, and copper mineralisation — all of which were targets of mining in this district.

The specimens display the typical earthy to resinous textures seen in sphalerite from New Zealand deposits, with colours ranging from brownish-orange to darker brown and grey, reflecting variations in iron content. Unlike the bright metallic sheen of galena, sphalerite often appears more subdued in hand specimen, though it is notably dense and heavy for its size.

Geologically, the Johnston’s United Mine forms part of a broader mineralised zone hosted within Paleozoic metasedimentary rocks, where hydrothermal fluids deposited sulfide minerals along fractures and veins. Sphalerite commonly occurs here alongside galena and pyrite, making this group particularly representative of the mine’s ore assemblage.

As a grouped specimen, this container provides an excellent comparative teaching set, illustrating natural variation within a single mineral species from one locality. It is well suited for museum displays, educational collections, or as a reference sample demonstrating zinc mineralisation in New Zealand’s mining history.

88g