Up for consideration is The Gilmore Mica Mining Company stock certificate from 1883:

 

#59

Issued to Charles D. Gilmore for 1,000 shares on October 1, 1883

Signed by Charles D. Gilmore as president and G. T. Chase as secretary

Incorporated in West Virginia

Capital stock of $200,000

Datelined Washington, D. C.

Uncancelled

Certificate in good condition

Vignette of an eagle, yellow underprint

 

The Gilmore Mica Mining Company owned quarries in Wheaton, Maryland (a suburb of Washington, D.C). Company mines operated from 1882 to approximately 1914; their mica quarries were in a granite pegmatite (igneous rock composed primarily of quartz, feldspar, and mica). Remains of the old Gilmore Mine (also called the Kensington Mica Mine) can be found in what is now the "Springbrook Forest" subdivision (Wheaton, Maryland) and the adjoining "Northwest Branch Park." The workings included two shafts, a number of ore dumps, and a large cut through the pegmatite. The operation used trenches to float the mica in the separating process. The mineral mica is used for a number of applications, including fire-resistant lamps and fireplace shields, and insulators, with a high electrical resistance.