Quartz with Hematite

specimen number:
8701005

location:
Soudan Mine, St. Louis Co., Minnesota, USA

description:
Very choice miniature for this old and well-known locality. Crystals of quartz, these with red hematite inclusions, coming off matrix. Small crystals of metallic micaceous hematite are scattered throughout. Very minimal damage present, specimens from this locality have never been plentiful.

The Soudan Mine, located in the Vermilion Range of northeastern Minnesota, is the oldest and deepest iron mine in the state, often called the Cadillac of underground mines due to the high purity of its ore. Geologically, the deposit consists of the Soudan Iron Formation, characterized by Precambrian-aged banded iron formations where intense folding and hydrothermal activity concentrated hematite within layers of chert and jasper. The site is mineralogically famous for its spectacular specimens of lustrous, steel-gray specular hematite associated with quartz crystals that are typically reddish or "ferruginous" in color due to the heavy inclusion of hematite within the quartz structure. Historically, mining and quarrying operations began in 1882 after the discovery of the high-grade hard ore by George Stuntz, with the first shipment leaving for Two Harbors in 1884. The mine was operated by the Oliver Iron Mining Company and later U.S. Steel, maintaining continuous production for nearly 80 years until its official closure in 1962 when deep underground methods became economically uncompetitive with open-pit taconite mining. Following its closure, the site was donated to the state and became the Soudan Underground Mine State Park, where it also served as a facility for high-energy physics research.

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