{"title":"Diopside","description":"\u003cp\u003e\u003cstrong\u003eDiopside\u003c\/strong\u003e is a rock-forming member of the \u003cstrong\u003eclinopyroxene group\u003c\/strong\u003e, a calcium-magnesium silicate (CaMgSi2O6) crystallizing in the monoclinic system as short, stubby prisms with a near-square cross-section. Hardness is about 6, with two cleavage planes intersecting at 93\/87 degrees, as is typical of all the pyroxenes. Color ranges from colorless and pale grey-green through grass-green, deep bottle-green, violet, and near-black, reflecting substitution of iron, chromium, or manganese for magnesium; it forms a complete chemical replacement series with hedenbergite, in which ferrous iron completely replaces magnesium in the structure. Geologically, diopside results from the thermal metamorphism of siliceous limestones or dolomites, and in calc-silicate skarns produced by contact metamorphism it is associated with wollastonite, vesuvianite, grossular, and tremolite. It also occurs in mantle-derived peridotites and kimberlites, where intensely green chromian varieties are easily spotted in the heavy mineral fraction of sand, making it an indicator mineral in diamond prospecting.\u003c\/p\u003e\u003cp\u003eClassic collector localities span several continents. In the United States, \u003cstrong\u003eDeKalb\u003c\/strong\u003e and the \u003cstrong\u003eCalvin Mitchell farm\u003c\/strong\u003e in St. Lawrence County, New York, along with the \u003cstrong\u003eTilly Foster Iron Mine\u003c\/strong\u003e in Putnam County, are famous for producing large, gemmy, transparent green crystals prized in historic collections. In Europe, \u003cstrong\u003eAla\u003c\/strong\u003e and \u003cstrong\u003eMount Monzoni\u003c\/strong\u003e in Italy's Alpine belt yield fine skarn-hosted green diopside, while the manganese deposit of \u003cstrong\u003ePraborna near Saint-Marcel\u003c\/strong\u003e, in Italy's Aosta Valley, is the type locality for the rare violet-blue variety \u003cstrong\u003eviolan\u003c\/strong\u003e. \u003cstrong\u003eSlyudyanka\u003c\/strong\u003e, on the shores of Lake Baikal in Russia, produces both deep-green chromian crystals known locally as \u003cstrong\u003ebaikalite\u003c\/strong\u003e and violet \u003cstrong\u003elavrovite\u003c\/strong\u003e, and \u003cstrong\u003eOutokumpu\u003c\/strong\u003e in Finland is another classic source of fine deep-green chrome-bearing crystals. Other notable occurrences include \u003cstrong\u003eNordmark\u003c\/strong\u003e and \u003cstrong\u003eLångban\u003c\/strong\u003e in Sweden, and \u003cstrong\u003eFranklin\u003c\/strong\u003e, New Jersey, both known for manganiferous varieties such as jeffersonite and schefferite.\u003c\/p\u003e\u003cp\u003eFor gem collectors, the most sought-after material is vivid \u003cstrong\u003echrome diopside\u003c\/strong\u003e from the \u003cstrong\u003eInagli deposit\u003c\/strong\u003e near Aldan in the \u003cstrong\u003eSakha Republic (Yakutia)\u003c\/strong\u003e, Siberia, discovered near diamond-bearing kimberlite pipes and marketed since the late 1980s as \"Siberian\" or \"Russian emerald\" for its intense chromium-driven green. Additional chrome diopside sources include Pakistan, Myanmar, Madagascar, Tanzania, Kenya, and Finland, while \u003cstrong\u003eNammakal\u003c\/strong\u003e in India supplies chatoyant black \u003cstrong\u003estar diopside\u003c\/strong\u003e showing a sharp four-rayed asterism from oriented magnetite needle inclusions. Collectors value diopside for this remarkable range of colors and habits within a single species — from museum-grade New York crystals to Siberian emerald-green gems and Alpine violan — combined with its role as a textbook skarn and mantle-indicator mineral for petrologists and diamond prospectors alike.\u003c\/p\u003e","products":[{"product_id":"af3-titanite-diopside","title":"TITANITE, DIOPSIDE, CLINOZOISITE \u0026 CLINOCHLORE – Rare Find, Bellecombe, Italy","description":"\u003cp\u003eA superb multi-mineral association bringing together Titanite, Diopside, Clinozoisite and Clinochlore on a single matrix, from the celebrated rodingite outcrops of Bellecombe in the Aosta Valley. The specimen shows well-formed crystal faces across all four species, with a striking contrast of lustre and tone that makes this classic Alpine locality piece a fine addition to a systematic or aesthetic 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 46 x 26 x 12 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 12 g\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProvenance:\u003c\/strong\u003e Bellecombe, Châtillon, Aosta Valley, Italy\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ITALMINERAL","offers":[{"title":"Default Title","offer_id":45732522983533,"sku":null,"price":29.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0693\/8027\/6333\/files\/AGC_20240726_200303051.jpg?v=1787997037"},{"product_id":"vog-granato-diopside-piemonte-0","title":"HESSONITE, CLINOCHLORE \u0026 DIOPSIDE – Red Alpine Garnet, Bellecombe, Italy","description":"\u003cp\u003eThis collector's specimen presents a striking association of red hessonite garnet crystals contrasted against green clinochlore and diopside, forming a naturally elegant color composition. The piece comes from Bellecombe, a celebrated Alpine rodingite locality in the Aosta Valley long prized by mineral collectors for its fine fissure minerals. The quality of crystallization and the balanced distribution of the three species make this an aesthetically remarkable and mineralogically interesting specimen for any serious 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 126 x 90 x 58 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 518 g\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProvenance:\u003c\/strong\u003e Bellecombe, Châtillon, Aosta Valley, Italy\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ITALMINERAL","offers":[{"title":"Default Title","offer_id":45737593077869,"sku":null,"price":99.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0693\/8027\/6333\/files\/IMG20250101014051.jpg?v=1788067195"}],"url":"https:\/\/www.italmineral.com\/collections\/diopside.oembed","provider":"ITALMINERAL","version":"1.0","type":"link"}