• Locality: Iron Mountain Mine, St. Francois County, Missouri

• ​Provenance: Old Stock

• ​Primary Minerals: Acicular Amphibole, Quartz, Hematite/Magnetite, Pyrite

• ​Weight: 322 Grams (11.4 oz)

• ​Dimensions: 3.25" x 2.25" x 1.25"

• ​Condition: Display Finished (Polished face, raw natural back)

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​A Window into Iron Mountain: Old Stock Provenance

Welcome to KeepsCache. Up for consideration is a brilliant 322-gram old-stock specimen from the famous Iron Mountain Mine in Missouri. Known for its massive, midwestern iron deposits, this specific piece captures a highly complex, localized hydrothermal event, beautifully showcased through a custom lapidary finish.

​The Mineral Assemblage

This specimen has been expertly polished on one primary display face, creating a glass-smooth window into a striking mineralogical contrast:

• ​The Inclusions (Amphibole): Suspended throughout the lighter quartz matrix are sharp, distinct, dark needle-like crystals. These acicular Amphibole inclusions create a beautiful, chaotic web-like structure locked permanently in the stone.

• ​The Iron Matrix: The surrounding host rock features the heavy, dark, metallic iron ores (hematite and magnetite) that made Iron Mountain legendary, grounding the piece with excellent specific gravity.

• ​The Sulfides: A close inspection of the polished face reveals bright, brassy metallic flashes of pyrite/chalcopyrite, adding brilliant metallic highlights against the dark iron and white quartz.

​Display and Finish

Measuring 3.25 x 2.25 inches, this piece is the perfect size for a dedicated cabinet display. The single polished face draws the eye into the depth of the amphibole needles, while the back and sides have been left completely raw and natural, preserving the rugged geological history of the specimen.

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