Pale crystals on rock matrix, noted as a Dolomite/Ankerite series specimen, with ferrous surfaces nearer the edges. Specimen collected in the region of Phoenixville, Chester Co., Pennsylvania. The I.D. of Ankerite in the region was dismissed as doubtful by Arthur Montgomery and removed from the list of approved species in Pennsylvania, however Ankerite was again reconfirmed by Heyl in a 1984 USGS study by XRD, specifically from specimens collected at the Wheatley Mine. The I.D. of Ankerite for these occurrences is entrenched in literature and is represented in most collection as such. Because chemical analysis or RXD is required to positively differentiate between the two species, the use of Ankerite as an I.D. for specimens from these occurrences will likely remain for practical/historical purposes. Specimen size: 5 x 3.5cm. From the PA Annex of my personal collection, acquired in 2005.
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