Cobaltite

specimen number:
2262319

location:
Tunaberg, Nykoping, Sodermanland Co., Sweden

description:
A small but very sharp lustrous crystal of cobaltite kept in a vial. The size provided is the size of the file. The specimen comes with several previous antique labels. These are shown at the end of the video. Very good for the Swedish classic.

The Tunaberg mining district, situated in Nykoping Municipality within Sodermanland County, Sweden, was a historic producer of copper and cobalt ores. Geologically, the deposit is located in the classic Bergslagen ore province and consists of a skarn-hosted, polymetallic sulfide system developed within Paleoproterozoic-age supracrustal rocks. Intense hydrothermal activity replaced limestone layers sandwiched between metavolcanic and metasedimentary sequences, depositing dense lenses of chalcopyrite, galena, and pyrrhotite, along with exceptionally well-formed crystals of cobaltite hosted within a gangue of diopside, calcite, and hornblende. Historically, primitive surface quarrying for copper began at the site during the late Middle Ages, with formal underground shaft operations expanding significantly in the seventeenth century under corporate ownership. The district achieved its peak industrial prominence during the late eighteenth century when cobalt was systematically mined to produce blue pigments for European porcelain factories, with the primary underground works operating intermittently through the nineteenth century. Due to the exhaustion of easily accessible ore zones and increased competition from cheaper overseas producers, large-scale industrial operations steadily contracted, leading to the permanent cessation of all commercial corporate mining at the Tunaberg property in 1892.

Ward's Natural Science Establishment, located in Rochester, New York, is one of the oldest and most influential scientific supply houses and mineral dealerships in United States history. Founded in 1862 by Henry Augustus Ward, a prominent professor of natural sciences at the University of Rochester, the institution began as a specialized studio to create, preserve, and distribute high-quality geological collections, taxidermy, and anatomical models for museums and universities. Geologically and mineralogically, the company became a primary global conduit for classic mineral specimens, systematically sourcing, cataloging, and distributing rare and aesthetic reference pieces from important international discoveries throughout the late 19th and 20th centuries. Historically, the business operated out of its iconic, sprawling College Avenue complex from 1869 until a devastating fire destroyed a large portion of its inventory and historical archives in 1930, prompting a relocation to its modern facilities on Ridge Road. The establishment played a foundational role in professionalizing American museum curation, serving as a training ground for legendary museum builders, and establishing standardized mineral kits that educated generations of geologists.

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