{"title":"Demantoid","description":"\u003cp\u003e\u003cstrong\u003eDemantoid\u003c\/strong\u003e is the fabled emerald-green gem variety of \u003cstrong\u003eandradite\u003c\/strong\u003e, the calcium-iron member of the \u003cstrong\u003egarnet group\u003c\/strong\u003e, with the chemical formula Ca₃Fe₂(SiO₄)₃. Trace amounts of chromium tint the crystal its coveted grass-to-forest green, while the mineral's cubic structure and lack of cleavage give it a Mohs hardness of 6.5–7 and an exceptionally high refractive index and dispersion — greater than diamond itself, which is exactly why 19th-century mineralogists coined the name from the Greek word for \"diamond-like.\" Well-formed dodecahedra and trapezohedra of demantoid rank among the most desirable crystal habits in the entire garnet family, prized as much by systematic mineral collectors as by gem cutters.\u003c\/p\u003e\u003cp\u003eThe type locality and still the benchmark source is Russia's \u003cstrong\u003eUral Mountains\u003c\/strong\u003e, especially the historic deposits around \u003cstrong\u003eNizhny Tagil\u003c\/strong\u003e, the \u003cstrong\u003eSysert district\u003c\/strong\u003e, and the Bobrovka River, first worked in the mid-19th century and famously used by \u003cstrong\u003eCarl Fabergé\u003c\/strong\u003e and Tiffany \u0026amp; Co. Classic Uralian specimens are prized for their radiating \u003cstrong\u003ebyssolite\u003c\/strong\u003e (fibrous amphibole) inclusions sprouting from a black \u003cstrong\u003echromite\u003c\/strong\u003e core, the so-called \"horsetail\" pattern that instantly authenticates Russian material. Since the 1990s, Namibia's \u003cstrong\u003eGreen Dragon Mine\u003c\/strong\u003e and other deposits in the \u003cstrong\u003eErongo region\u003c\/strong\u003e near Karibib have become the world's leading commercial source, yielding cleaner, often larger crystals with a brighter, more purely green tone, typically formed in skarn contact zones rather than the ultramafic serpentinite settings of the Urals. Other notable sources include \u003cstrong\u003eAntetezambato\u003c\/strong\u003e and various localities in Madagascar, producing yellow-green to deep-green stones sometimes showing Russian-style inclusion patterns; Iran; Val Malenco in Lombardy, Italy, source of fibrous-matrix specimens on chrysotile asbestos; and smaller occurrences in Pakistan, Afghanistan, Eritrea, Sri Lanka, and California.\u003c\/p\u003e\u003cp\u003eFine demantoid crystals over two carats are genuinely rare, and museum-grade Uralian pieces with sharp horsetail inclusions can command prices rivaling top emeralds. Collectors distinguish demantoid from its sister andradite varieties — the yellow \u003cstrong\u003etopazolite\u003c\/strong\u003e and opaque black \u003cstrong\u003emelanite\u003c\/strong\u003e — and from other green garnets like \u003cstrong\u003euvarovite\u003c\/strong\u003e and tsavorite, making a well-documented, locality-labeled demantoid specimen, whether a lustrous Uralian crystal on matrix or a gemmy Namibian trapezohedron, a centerpiece for any serious garnet or Ural mineral collection.\u003c\/p\u003e","products":[{"product_id":"demantoid-garnet-crystals-on-matrix-belqeys-mt-iran","title":"DEMANTOID GARNET – Vivid Green Crystals on matrix, Belqeys Mt., Iran","description":"\u003cp\u003eA striking cluster of Demantoid, the emerald-green gem variety of Andradite garnet, from the remote and highly regarded locality of Belqeys Mountain in northwestern Iran. The crystals show an intense, saturated green colour with glossy, well-defined faces that catch the light beautifully, forming a well-developed aggregate directly on matrix.\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 47 x 43 x 22 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 30 g\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProvenance:\u003c\/strong\u003e Belqeys Mountain, Takab County, West Azerbaijan Province, Iran\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ITALMINERAL","offers":[{"title":"Default Title","offer_id":45735992295533,"sku":null,"price":249.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0693\/8027\/6333\/files\/IMG20260807181848.jpg?v=1788055113"}],"url":"https:\/\/www.italmineral.com\/collections\/demantoid.oembed","provider":"ITALMINERAL","version":"1.0","type":"link"}