A large grouping of bright lustrous bladed terminated crystals of ferberite without matrix. This is naturally crystallized all around and in good condition. Minor pale colorless fluorapatite present, as well as micro siderite. The specimen comes with a previous label from the collection of Ray DeMark.The Panasqueira Mines in Beira Baixa, Portugal, opened in 1898 and, aside from a brief temporary closure in 2003, remain actively in operation today. Geologically, the deposit is hosted within a sequence of late Precambrian to Cambrian metasedimentary rocks, primarily consisting of greenschist-facies shales, slates, and greywackes of the Beira schist formation. The mineralization occurs as a sub-horizontal system of quartz veins rich in tungsten, tin, and copper, which are genetically related to an underlying hidden Hercynian granitic pluton emplaced during the Late Carboniferous period.
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