Wolframite Topaz Fluorite Sericite Zinnwaldite Einstein Mine Silvermine MO Cox For Sale

Einstein Mine Wolframite in Topaz-Fluorite Greisen with Zinnwaldite & Sericite – Ex-Charley Cox Collection – Silver Mine, Madison Co., Missouri

Deep beneath the St. Francois Mountains, roughly 1.4 to 1.5 billion years ago, hot fluids from late-stage granite magma forced their way into joints in the surrounding igneous rock. Those fluids carried fluorine, lithium, and tungsten, and they changed the rock they passed through into greisen, a crystalline mix of topaz, quartz, and mica. As the veins cooled, black blades of wolframite, the tungsten ore, grew in radiating sprays. Later pulses brought purple fluorite and silky green sericite, which filled the gaps. Over time, weathering near the surface stained the whole piece in rust, maroon, and gold iron oxides, and a few spots carry an iridescent purple sheen. (Grokipedia)

This specimen comes from the mine that gave the Silver Mine district its name. Systematic prospecting started in 1877, and in 1879 the Einstein Silver Mining Company was formed. It built a large masonry dam across the St. Francois River for power, along with a concentrating plant and a furnace. Between 200 and 300 men worked there at its height, and an incline was sunk to 180 feet. The silver operation eventually failed. Then the First World War created demand for tungsten, and in February 1916 the Madison Mining Corporation of New York reopened the old Einstein Silver Mine, mainly for the tungsten in its ore. The old dam still stands on the river today. (Einstein Mine, Silver Mine, Fredericktown Mining District, Madison County, Missouri, USA +2)

Ore studies of the district describe 24 primary minerals deposited in several stages. The early greisen stage produced topaz, sericite, wolframite, and zinnwaldite, among others, and fluorite and chlorite came in later. This piece records both stages in one hand specimen. (Springer)

Provenance: Ex-Charley Cox Collection, from historic Silver Mine district material. Old-stock pieces like this are no longer coming out of these long-closed workings.

Minerals present:

Wolframite: black radiating bladed sprays with submetallic flashes

Topaz: part of the greisen matrix

Quartz: drusy and small crystal pockets

Fluorite: purple

Zinnwaldite: lithium-iron mica

Sericite: pale to olive green silky mica crusts

Iron oxides: limonite and hematite staining, with iridescent patches

Specs:

Weight: 173 g

Dimensions: 2.5" x 2.25" x 1.25"

Condition: Completely natural rough, not cut or polished. It feels noticeably heavy for its size because of the tungsten mineral.

Free shipping. Best Offer considered.

Keywords

Wolframite, hübnerite, ferberite, tungsten ore, tungsten mineral, topaz, topaz greisen, greisen, fluorite, purple fluorite, zinnwaldite, lithium mica, sericite, green mica, gilbertite, muscovite, quartz, drusy quartz, limonite, hematite, iron oxide, iridescent, Einstein Mine, Einstein Silver Mine, Silver Mine, Silvermine, Silvermines, Fredericktown Mining District, Fredericktown, Madison County, Missouri, MO, St. Francois Mountains, St. Francois River, Ozark Uplift, Precambrian, Mesoproterozoic, WWI tungsten, 1916 tungsten mine, Madison Mining Corporation, Charley Cox Collection, Cox Collection, old collection, historic mine, closed mine, Missouri minerals, Missouri mineral specimen, Missouri tungsten, Missouri silver mine, polymetallic, Ag-W-Sn deposit, hydrothermal vein, pneumatolytic, rough specimen, natural specimen, collector specimen, locality specimen, rock collection, rockhound, lapidary rough