{"title":"Arsenopyrite","description":"\u003cp\u003e\u003cstrong\u003eArsenopyrite\u003c\/strong\u003e is an iron arsenic sulfide with the formula \u003cstrong\u003eFeAsS\u003c\/strong\u003e, one of the most widespread minerals containing the element \u003cstrong\u003earsenic\u003c\/strong\u003e. It crystallizes in the monoclinic system, historically mistaken for orthorhombic due to its near-perfect pseudo-orthorhombic symmetry, and typically forms sharply striated prismatic crystals with wedge-shaped terminations, silver-white to steel-gray in color with a metallic luster and black streak. With a Mohs hardness of 5.5–6 and a notably high specific gravity around 6.1, specimens have real heft in hand. Crystals often twin on {101} and {100}, sometimes forming attractive star-shaped trillings, and the mineral gives off a characteristic garlic odor when struck. As the principal ore of arsenic and a common host for invisible gold in orogenic gold deposits, arsenopyrite has long been mined alongside precious metals, and its cobalt-bearing variety, danaite, grades toward the related species glaucodot.\u003c\/p\u003e\u003cp\u003eThe world's most celebrated locality for fine arsenopyrite is \u003cstrong\u003ePanasqueira\u003c\/strong\u003e in Portugal, whose tin-tungsten veins produce lustrous, sharply striated silvery crystals perched on snow-white quartz alongside honey-colored siderite and brilliant green fluorapatite. Classic European occurrences include \u003cstrong\u003eFreiberg\u003c\/strong\u003e in Saxony, Germany — historically mined as mispickel — plus the \u003cstrong\u003eHimmelfahrt Mine\u003c\/strong\u003e and Zug locality nearby, the \u003cstrong\u003eStari Trg mine at Trepča\u003c\/strong\u003e in Kosovo\/Serbia, numerous tin and copper mines across \u003cstrong\u003eCornwall\u003c\/strong\u003e and Devonshire in England, and the Swedish deposits of Sala, Tunaberg, Stollberg, Nordmark, and \u003cstrong\u003eBoliden\u003c\/strong\u003e. Exceptional crystals also come from Asia, notably the \u003cstrong\u003eYaogangxian Mine\u003c\/strong\u003e in Hunan and the Dachang district in China, prized for complex wheel-and-cog-like crystals approaching 10 cm, and the \u003cstrong\u003eObira Mine\u003c\/strong\u003e in Japan. Further important sources include the historic gold-bearing veins of the \u003cstrong\u003eDeloro district\u003c\/strong\u003e in Ontario, Canada, the silver mines of \u003cstrong\u003ePotosí\u003c\/strong\u003e in Bolivia, the Santa Eulalia district in Chihuahua, Mexico, and Dalnegorsk in Russia.\u003c\/p\u003e\u003cp\u003eCollectors prize arsenopyrite for its sculptural geometry and mirror-bright metallic sheen, which can rival pyrite or stibnite, as well as for the striking contrasts it forms with associated minerals such as quartz, fluorite, siderite, cassiterite, and fluorapatite. It is a staple of serious sulfide and old European vein collections, valued equally for crystalline perfection and for the mining history attached to classic localities like Freiberg, Panasqueira, and Trepča. Because good crystals from key districts can reach several centimeters while true museum-caliber matrix groups remain genuinely scarce, arsenopyrite offers something for every level of mineral collector, from affordable thumbnails to important cabinet specimens.\u003c\/p\u003e","products":[{"product_id":"fa13-arsenopirite-quarzo","title":"ARSENOPYRITE \u0026 QUARTZ – Iridescent Blue Flash, Julcani Mine, Peru","description":"\u003cp\u003eA richly crystallized cluster of iridescent Arsenopyrite crystals from the historic Julcani Mine in Peru, paired with clear hyaline Quartz for a striking aesthetic contrast. The well-formed crystals show sharp, striated faces and a strong play of blue and purple tarnish colors that shift with the light, making this a genuinely rare and collector-grade aesthetic specimen.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eMineral Data:\u003c\/strong\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDimensions:\u003c\/strong\u003e 78 x 66 x 33 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 282 g\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProvenance:\u003c\/strong\u003e Julcani Mine, Julcani, Huancavelica, Peru\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ITALMINERAL","offers":[{"title":"Default Title","offer_id":45733443305581,"sku":null,"price":99.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0693\/8027\/6333\/files\/IMG20251105143959.jpg?v=1788005321"}],"url":"https:\/\/www.italmineral.com\/collections\/arsenopyrite.oembed","provider":"ITALMINERAL","version":"1.0","type":"link"}