{"title":"Microcline","description":"\u003cp\u003e\u003cstrong\u003eMicrocline\u003c\/strong\u003e is a rock-forming potassium feldspar with the chemical formula KAlSi₃O₈, belonging to the \u003cstrong\u003efeldspar group\u003c\/strong\u003e alongside orthoclase and sanidine within the K-feldspar series. It is the fully ordered, low-temperature triclinic polymorph of potassium feldspar, distinguished from monoclinic orthoclase by a slight departure from 90° in its cleavage angles — a feature reflected in its very name, coined in 1830 from the Greek for \"little\" and \"to incline\". Common in granites, syenites, and granitic pegmatites, microcline often displays the diagnostic cross-hatched \"tartan\" twinning visible under polarized light, and frequently intergrows with albite as \u003cstrong\u003eperthite\u003c\/strong\u003e. While abundant as a rock-forming mineral, well-formed crystals and gem-quality varieties are prized by collectors and are the true focus of specimen mining.\u003c\/p\u003e\u003cp\u003eClassic crystallized microcline comes from a handful of celebrated localities. \u003cstrong\u003eBaveno\u003c\/strong\u003e, on Lake Maggiore in Italy, is the type locality for the famous \"Baveno twin\" law seen worldwide. Sharp, gemmy crystals associated with \u003cstrong\u003eaegirine\u003c\/strong\u003e are collected at \u003cstrong\u003eMount Malosa\u003c\/strong\u003e in Malawi, while large crystals also come from the \u003cstrong\u003eErongo Mountains\u003c\/strong\u003e in Namibia, the \u003cstrong\u003eShigar Valley\u003c\/strong\u003e near Skardu in Pakistan, and the \u003cstrong\u003ePapachacra\u003c\/strong\u003e pegmatites of Catamarca, Argentina. North American classics include \u003cstrong\u003eMont Saint-Hilaire\u003c\/strong\u003e in Quebec, the pegmatites of \u003cstrong\u003eChester County\u003c\/strong\u003e, Pennsylvania, and \u003cstrong\u003eMoat Mountain\u003c\/strong\u003e, New Hampshire, historic sources of large, well-formed specimens for museum and study collections.\u003c\/p\u003e\u003cp\u003eThe most commercially and aesthetically important variety is \u003cstrong\u003eamazonite\u003c\/strong\u003e, a vivid green to blue-green microcline whose color is attributed to trace lead and structural water. Fine amazonite crystals, often combined with smoky quartz or albite, are found at \u003cstrong\u003ePikes Peak\u003c\/strong\u003e in Colorado and the historic \u003cstrong\u003eMorefield Mine\u003c\/strong\u003e near Amelia, Virginia — long considered the finest American source. Other important amazonite localities include the \u003cstrong\u003eKola Peninsula\u003c\/strong\u003e in Russia, \u003cstrong\u003eMinas Gerais\u003c\/strong\u003e in Brazil, and pegmatites in Madagascar and Mogok, Myanmar. Beyond amazonite, microcline is also cut as sunstone in certain occurrences. Collectors value microcline specimens for their sharp crystal habit, striking twinning, and the vivid amazonite color variety, making this common feldspar a perennial favorite for both systematic mineral collections and display-quality pieces.\u003c\/p\u003e","products":[{"product_id":"fa14-zircone-aegirina-ortoclasio","title":"ZIRCON on AEGIRINE – Black Crystals on Microcline, Mount Malosa, Malawi","description":"\u003cp\u003eA striking cluster showcasing numerous lustrous black Zircon crystals with sharp square prismatic bodies and distinctive pyramidal terminations, perched on dark, needle-like Aegirine and set against a contrasting white Microcline feldspar matrix. This aesthetic combination-piece comes from Mount Malosa, a world-renowned alkaline pegmatite locality in Malawi celebrated among collectors for producing some of the finest Aegirine crystals on Earth, along with well-formed Zircon and rare associated species. The excellent crystal formation on this specimen allows the individual faces and terminations to be clearly appreciated, making it a highly decorative and scientifically interesting piece for any serious mineral collection.\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 50 x 37 x 30 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 61 g\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProvenance:\u003c\/strong\u003e Mount Malosa, Zomba, Southern Region, Malawi\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ITALMINERAL","offers":[{"title":"Default Title","offer_id":45735697285229,"sku":null,"price":75.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0693\/8027\/6333\/files\/IMG20251219220217.jpg?v=1788050003"}],"url":"https:\/\/www.italmineral.com\/collections\/microcline.oembed","provider":"ITALMINERAL","version":"1.0","type":"link"}