Wavellite

specimen number:
1052744

location:
General Trimble's Mine, Chester Co., Pennsylvania, USA

description:

Fine old classic specimen from Pennsylvania, the specimen showing stalactitic goethite, these coated with white crystallized wavellite. This is not perfect, but still very good for something collected in the late 19th century. The specimen comes with an antique label as shown at the end of the video. Note that the old label gives the locality as White Horse. This evidently was a small village near the mine in the late 1800s.

The General Trimble mine, situated near the historic village of White Horse in East Whiteland Township, Chester County, Pennsylvania, was a notable nineteenth-century open-cut iron mining operation. Geologically, the deposit was located along a highly altered contact zone where Cambrian-age Antietam quartzite met Ordovician-age Conestoga limestone, creating a heavily weathered, clay-rich environment filled with residual iron oxides like goethite and limonite. This specific geochemical setting was uniquely enriched with phosphate, which allowed for the localized crystallization of exceptional wavellite specimens, occurring as sharp radiating spherical aggregates and hemispherical crusts within the soft iron ore matrix. Historically, formal surface excavation and open-pit quarrying at the site commenced around the mid-nineteenth century to supply iron ore to regional blast furnaces. Operations were carried out intermittently under various owners, including the prominent civil engineer and military officer Isaac Trimble, until the progressive depletion of high-grade commercial ore and competition from larger domestic iron ranges forced the permanent cessation of all mining activities at the property around 1890.

Dr. Ludwig Eger (active c. 1870-1915) was a highly respected Austrian mineral dealer based in Vienna who played a significant role in the distribution of Central European and Alpine mineral specimens during the late 19th and early 20th centuries. Operating under the firm name "Dr. L. Eger," his business was situated in the heart of Vienna, a primary hub for scientific exchange during the Austro-Hungarian Empire. Eger was noted for his professional, academic approach to the mineral trade, often supplying high-quality, systematic collections to universities and major museums throughout Europe and North America. His labels are easily recognized by their classic 19th-century typography, typically featuring "Dr. L. Eger, Wien" (the German name for Vienna) and providing detailed locality and species data in a formal, structured format. In addition to minerals, Eger dealt in paleontological and zoological specimens, as was common for the natural history establishments of the time.

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