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.