{"product_id":"1-60-carat-natural-cobalt-blue-spinel-tanzania","title":"1.60 Carat Natural Cobalt Blue Spinel – Tanzania","description":"\u003cp\u003e\u003cspan\u003eA distinctive \u003c\/span\u003e\u003cspan\u003e1.60 carat natural cobalt spinel from Tanzania\u003c\/span\u003e\u003cspan\u003e, displaying a sophisticated deep blue color with brighter blue flashes as the stone moves through the light.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eCut in an \u003c\/span\u003e\u003cspan\u003eoctagonal step-cut\u003c\/span\u003e\u003cspan\u003e, the stone has a strong geometric appearance with broad, structured facets that emphasize its depth of color. Cobalt-bearing blue spinel occupies a particularly interesting niche within the spinel family, with fine natural examples sought by collectors for their unusual blue coloration and relative scarcity.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe accompanying gemological report identifies this specimen specifically as \u003c\/span\u003e\u003cspan\u003eNatural Cobalt Spinel\u003c\/span\u003e\u003cspan\u003e, with \u003c\/span\u003e\u003cspan\u003eTanzanian origin\u003c\/span\u003e\u003cspan\u003e and \u003c\/span\u003e\u003cspan\u003eno indication of heat treatment\u003c\/span\u003e\u003cspan\u003e.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eGemstone Details\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cspan\u003eGemstone:\u003c\/span\u003e\u003cspan\u003e Natural Cobalt Spinel\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eWeight:\u003c\/span\u003e\u003cspan\u003e 1.60 carats\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eColor:\u003c\/span\u003e\u003cspan\u003e Blue\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eOrigin:\u003c\/span\u003e\u003cspan\u003e Tanzania\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eCut:\u003c\/span\u003e\u003cspan\u003e Octagon Cut\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eMeasurements:\u003c\/span\u003e\u003cspan\u003e 6.54 × 5.77 mm \u003c\/span\u003e\u003cspan\u003e(see report for complete depth measurement)\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eTreatment:\u003c\/span\u003e\u003cspan\u003e No indication of heat\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eHardness:\u003c\/span\u003e\u003cspan\u003e 8 on the Mohs scale\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eCondition:\u003c\/span\u003e\u003cspan\u003e Loose gemstone\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eReport:\u003c\/span\u003e\u003cspan\u003e AIG – American International GemLab\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003eReport No.:\u003c\/span\u003e\u003cspan\u003e GEM20260827178198\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003eA Collector’s Blue Spinel\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eBlue is among the more unusual colors found in natural spinel. In certain blue spinels, cobalt can contribute to the characteristic blue coloration that has made cobalt-bearing material particularly interesting to gemstone collectors.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eUnlike blue sapphire, spinel is \u003c\/span\u003e\u003cspan\u003esingly refractive\u003c\/span\u003e\u003cspan\u003e, giving well-cut stones their own distinctive optical character. With a hardness of \u003c\/span\u003e\u003cspan\u003e8\u003c\/span\u003e\u003cspan\u003e, spinel also combines rarity and beauty with enough durability to make it suitable for fine jewelry.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThis specimen’s octagonal step cut creates a completely different appearance from the more common brilliant-style spinel, producing broad flashes of blue and emphasizing the stone’s architectural geometry.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eNatural \u0026amp; Unheated\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe report states \u003c\/span\u003e\u003cspan\u003e“No Indication of Heat.”\u003c\/span\u003e\u003cspan\u003e The stone is sold as the exact loose gemstone pictured, allowing the buyer to preserve it as a collector specimen or commission a one-of-a-kind ring or pendant around it.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eOffered at $3,500\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eMacro photography is used to show the gemstone in detail. Magnification and lighting can reveal inclusions and internal characteristics that may be considerably less apparent during normal viewing.\u003c\/span\u003e\u003c\/p\u003e","brand":"Rogue Valley Gem Exchange ","offers":[{"title":"Default Title","offer_id":52431078162728,"sku":null,"price":3500.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1007\/4059\/6008\/files\/94169E74-5BDB-4D3C-8B2B-882237EF5620.png?v=1789807942","url":"https:\/\/shop.roguevalleygemexchange.com\/products\/1-60-carat-natural-cobalt-blue-spinel-tanzania","provider":"Rogue Valley Gem Exchange ","version":"1.0","type":"link"}