{"title":"Albite","description":"\u003cp\u003e\u003cstrong\u003eAlbite\u003c\/strong\u003e is the sodium-rich end-member of the \u003cstrong\u003eplagioclase feldspar\u003c\/strong\u003e series, with the formula NaAlSi3O8, forming a continuous solid-solution with calcium-rich \u003cstrong\u003eanorthite\u003c\/strong\u003e. Crystallizing in the triclinic system, it typically shows repeated \u003cstrong\u003ealbite law\u003c\/strong\u003e and \u003cstrong\u003epericline law\u003c\/strong\u003e twinning, producing the fine striations visible on cleavage faces that are a key diagnostic feature for collectors and mineralogists alike. Pure albite is white to colorless with a vitreous to pearly luster and a hardness of 6 to 6.5, though it can appear pale green, blue, or show a floating sheen in the \u003cstrong\u003eperisterite\u003c\/strong\u003e variety, prized as a moonstone-like gem material.\u003c\/p\u003e\u003cp\u003eTypical albite occurs as a common rock-forming mineral in granites, alpine clefts, and especially in granitic pegmatites, where it often develops as the elegant blade-like habit known as \u003cstrong\u003ecleavelandite\u003c\/strong\u003e, frequently intergrown with \u003cstrong\u003emuscovite\u003c\/strong\u003e, \u003cstrong\u003elepidolite\u003c\/strong\u003e, \u003cstrong\u003etourmaline\u003c\/strong\u003e, \u003cstrong\u003espessartine\u003c\/strong\u003e, and \u003cstrong\u003eapatite\u003c\/strong\u003e. The classic pegmatite source is \u003cstrong\u003eMinas Gerais\u003c\/strong\u003e, Brazil, particularly the Doce and Jequitinhonha valleys and localities such as \u003cstrong\u003eDivino das Laranjeiras\u003c\/strong\u003e and \u003cstrong\u003eGaliléia\u003c\/strong\u003e, producing enormous, gemmy cleavelandite plates. In the United States, superb clear crystals come from \u003cstrong\u003eAmelia Court House\u003c\/strong\u003e, Virginia, and from the San Diego County pegmatites of \u003cstrong\u003ePala\u003c\/strong\u003e and \u003cstrong\u003eMesa Grande\u003c\/strong\u003e, including the \u003cstrong\u003eHimalaya Mine\u003c\/strong\u003e. Exceptional, large, well-formed crystals are also mined from the pegmatites of \u003cstrong\u003eGilgit\u003c\/strong\u003e and the \u003cstrong\u003eShigar Valley\u003c\/strong\u003e in Pakistan and from \u003cstrong\u003eNuristan\u003c\/strong\u003e, Afghanistan.\u003c\/p\u003e\u003cp\u003eParticular, highly collectible albite comes from Alpine-cleft environments, where slow hydrothermal growth yields elongated, gemmy \u003cstrong\u003epericline\u003c\/strong\u003e-twinned crystals up to decimeter size. Famous examples originate from the \u003cstrong\u003eSt. Gotthard\u003c\/strong\u003e massif in Switzerland, the \u003cstrong\u003eVal di Vizze\u003c\/strong\u003e and \u003cstrong\u003eValle Aurina\u003c\/strong\u003e deposits in Italy, and the French alpine fissures of \u003cstrong\u003eSt-Christophe-en-Oisans\u003c\/strong\u003e and \u003cstrong\u003eSt-Véran\u003c\/strong\u003e. Fine crystals also occur in the Italian pegmatites of \u003cstrong\u003eBaveno\u003c\/strong\u003e, Piedmont, and in Canada at \u003cstrong\u003eMont Saint-Hilaire\u003c\/strong\u003e and the \u003cstrong\u003eFrancon quarry\u003c\/strong\u003e near Montreal. Albite additionally forms the feldspar component of \u003cstrong\u003emaw-sit-sit\u003c\/strong\u003e, the ornamental albite-jadeite rock from Myanmar. Collectors seek albite for its crisp twin striations, association with rare pegmatite minerals, the translucent beauty of cleavelandite plates, and the scientific value of well-formed specimens in demonstrating triclinic crystallography and feldspar twin laws.\u003c\/p\u003e","products":[],"url":"https:\/\/www.italmineral.com\/collections\/albite.oembed","provider":"ITALMINERAL","version":"1.0","type":"link"}