{"title":"Corundum","description":"\u003cp\u003e\u003cstrong\u003eCorundum\u003c\/strong\u003e is crystalline aluminum oxide (Al2O3), one of the hardest natural minerals on Earth (9 on the Mohs scale, second only to diamond) and the parent species of two of the world's most coveted gemstones: red \u003cstrong\u003eruby\u003c\/strong\u003e (colored by chromium) and blue-to-fancy-colored \u003cstrong\u003esapphire\u003c\/strong\u003e (colored by iron and titanium). Trace element substitutions produce a remarkable color range, while trapiche and star (asteriated) varieties, caused by rutile silk inclusions, are especially prized by collectors.\u003c\/p\u003e\u003cp\u003eTypical gem-quality corundum comes from classic alluvial and metamorphic deposits such as \u003cstrong\u003eMogok\u003c\/strong\u003e and \u003cstrong\u003eMong Hsu\u003c\/strong\u003e in Myanmar, \u003cstrong\u003eRatnapura\u003c\/strong\u003e in Sri Lanka, Kashmir, and Ilakaka in Madagascar. Exceptional collector specimens include the small but flawless, untreated blue crystals of \u003cstrong\u003eYogo Gulch\u003c\/strong\u003e, Montana, prized for their uniform saturation and natural luster, and the historic hexagonal rubies of the \u003cstrong\u003eCowee Valley\u003c\/strong\u003e in North Carolina. Non-gem, rock-forming corundum defines the famous emery deposits of \u003cstrong\u003eNaxos\u003c\/strong\u003e, Greece, and the corundum-syenite belts of Ontario, Canada, while opaque rubies in green zoisite matrix come from \u003cstrong\u003eLongido\u003c\/strong\u003e and \u003cstrong\u003eWinza\u003c\/strong\u003e in Tanzania, and Jegdalek, Afghanistan.\u003c\/p\u003e\u003cp\u003eCollectors seek natural corundum for its unmatched hardness, saturated color, and crystallographic beauty, from barrel-shaped sapphire crystals to tabular Yogo gems and classic hexagonal ruby prisms. Untreated, well-formed specimens from historic type localities remain among the most desirable pieces in any hard-mineral or gemstone collection.\u003c\/p\u003e","products":[{"product_id":"epidoto-verde-su-quarzo-da-cavrein-svizzera-copy","title":"RUBY CRYSTALS – Red Corundum from Madagascar – UV Reactive Hexagonal Crystals","description":"\u003cp\u003eNatural Ruby crystals from Ampanihy District, Madagascar. These red corundum crystals display a well-defined hexagonal habit, intense natural coloration, and strong UV reactivity, glowing bright red under ultraviolet light. Rare collector specimens with excellent aesthetic and mineralogical value.\u003cbr\u003e\u003cbr data-start=\"763\" data-end=\"766\"\u003e\u003cstrong data-start=\"766\" data-end=\"783\"\u003eMineral Data:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong data-start=\"784\" data-end=\"799\"\u003eDimensions:\u003c\/strong\u003e\n\u003cul\u003e\n\u003cli\u003eLarge 15–10 mm, \u003c\/li\u003e\n\u003cli\u003eMedium 9–5 mm,\u003c\/li\u003e\n\u003cli\u003eSmall 4 mm \u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong data-start=\"842\" data-end=\"857\"\u003eProvenance:\u003c\/strong\u003e Ampanihy District, Atsimo-Andrefana, Madagascar\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ITALMINERAL","offers":[{"title":"Small","offer_id":44328256405613,"sku":null,"price":9.0,"currency_code":"EUR","in_stock":true},{"title":"Medium","offer_id":44328256438381,"sku":null,"price":19.0,"currency_code":"EUR","in_stock":true},{"title":"Large","offer_id":44328256471149,"sku":null,"price":29.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0693\/8027\/6333\/files\/imgi_41_AGC_20240601_030445505.jpg?v=1772658651"},{"product_id":"fa16-rubino-madagascar-0","title":"RUBY – Purple CORUNDUM, UV Reactive Crystal from Zazafotsy, Madagascar","description":"\u003cp\u003eA striking corundum crystal, variety ruby, showing a rich purple-red color with visible zoning between red and mauve tones depending on the light source. The 1.8cm crystal is perfectly formed, with sharp, well-defined faces sitting on a dark schist matrix that enhances the contrast and overall aesthetic appeal. The specimen displays a notable reaction under longwave ultraviolet light, a feature that is well documented for corundum from this specific Malagasy locality and adds further scientific and display interest to the piece.\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 58 x 43 x 33 mm (crystal 1.8 cm)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 74 g\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProvenance:\u003c\/strong\u003e Zazafotsy Quarry, Zazafotsy, Ihosy District, Ihorombe, Madagascar\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ITALMINERAL","offers":[{"title":"Default Title","offer_id":45460217725037,"sku":null,"price":69.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0693\/8027\/6333\/files\/IMG20260423234029.jpg?v=1784131402"}],"url":"https:\/\/www.italmineral.com\/collections\/corundum.oembed","provider":"ITALMINERAL","version":"1.0","type":"link"}