Millerite

specimen number:
2062923

location:
US highway 27 roadcut, Halls Gap, Lincoln Co., Kentucky, USA

description:
An open geode half lined with glistening crystals of quartz and very richly filled with bronze lustrous metallic wispy acicular crystals of millerite. Classic locality for the species. The specimen comes with a previous label from the collection of Ray DeMark. His label notes that the specimen was collected by Bill Mackenzie in April, 1995.

The US Highway 27 roadcut at Halls Gap in Lincoln County, Kentucky, cuts through Mississippian-age sedimentary rock layers containing geode-bearing strata. Created during highway construction, the site gained world renown among mineral collectors for producing exceptional geodes lined with quartz, chalcedony, and calcite. Most notably, this locality became a classic North American type site for millerite, appearing as delicate, hair-like, brassy crystal sprays nestled inside these hollow cavities. Over the decades, enthusiastic hobbyists and field collectors heavily worked the steep shale slopes for these prized specimens, though collecting activity has since become limited due to weathering, safety hazards, and changing roadside access.

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