Ferberite with Quartz, Siderite, Muscovite - image 1

Ferberite with Quartz, Siderite, Muscovite

Unknown Owner

Classic combination piece for this locality with lustrous bladed crystals of ferberite in a cluster with gemmy colorless crystals of quartz. Small crystals of platy siderite are scattered throughout. This is in good condition all around.The Panasqueira Mines are located in the Castelo Branco District of central Portugal and represent one of the largest and most significant tungsten deposits in the world. Geologically, the site is a classic hydrothermal vein system hosted within the Beira Schist, a sequence of Precambrian to Cambrian metasedimentary rocks. The mineralization was triggered by the intrusion of a Hercynian-aged granite laccolith, which generated high-pressure fluids that opened a vast network of horizontal and sub-horizontal "flat" veins. These veins contain a complex mineral assembly formed during several stages of hydrothermal activity, primarily focusing on wolframite, cassiterite, and chalcopyrite. Historically, mining at Panasqueira began in the late 19th century, around 1886, and the site became a vital strategic source of tungsten for Europe throughout both World Wars.For mineral collectors, Panasqueira is legendary for producing world-class specimens characterized by exceptional crystal size and luster. The mine is perhaps most famous for its magnificent ferberite (wolframite) crystals, which often occur as large, jet-black metallic blades. These are frequently found in aesthetic association with "book-like" clusters of silvery muscovite, glassy quartz prisms, and exceptionally large, purple or green fluorapatite crystals. Other notable minerals from the site include sharp arsenopyrite crystals and translucent, zoned fluorite. Because the mine has remained in near-continuous operation for over 135 years, it has provided a steady supply of specimens that are foundational to many of the world's most prestigious mineral collections, serving as a primary reference for European granite-related ore deposits.