{"product_id":"2-63-carats-natural-cobalt-blue-spinel-tanzania-blue-to-purple-color-change","title":"2.63 Carats Natural Cobalt Blue Spinel - Tanzania\n(Blue-to-Purple Color Change)","description":"\u003cp\u003e\u003cspan\u003eAn extraordinary \u003c\/span\u003e\u003cspan\u003e2.63-carat natural cobalt spinel from Tanzania\u003c\/span\u003e\u003cspan\u003e, distinguished by a documented \u003c\/span\u003e\u003cspan\u003eblue-to-purple color change\u003c\/span\u003e\u003cspan\u003e. Under different lighting conditions, the gemstone transitions from a deep cobalt-blue appearance toward rich violet and purple tones, giving the stone two distinctly different personalities.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe gemstone has been fashioned into a \u003c\/span\u003e\u003cspan\u003eheart faceted cut\u003c\/span\u003e\u003cspan\u003e, an uncommon and visually striking presentation for a cobalt spinel of this size. Its faceting produces flashes ranging from midnight and royal blue to brighter electric-blue highlights, while the alternate lighting appearance introduces violet and purple.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe accompanying gemological report identifies the stone as \u003c\/span\u003e\u003cspan\u003eNATURAL COBALT SPINEL (COLOR CHANGE)\u003c\/span\u003e\u003cspan\u003e and records \u003c\/span\u003e\u003cspan\u003e“No Indication Of Heat.”\u003c\/span\u003e\u003cspan\u003e The report further notes that the color change can be observed under incandescent lighting.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eCobalt-bearing blue spinel occupies a distinctive position among collector gemstones. Unlike ordinary dark-blue spinel, desirable cobalt spinel derives its celebrated blue coloration from the presence of cobalt within the crystal structure. Stones combining substantial size, documented cobalt identification and a noticeable color-change phenomenon represent an especially interesting category for serious colored-gem collectors.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eNatural internal characteristics remain visible and have not been concealed in the photography.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eGemstone:\u003c\/span\u003e\u003cspan\u003e Natural Cobalt Spinel (Color Change)\u003c\/span\u003e\u003cspan\u003e\u003cbr\u003e \u003c\/span\u003e\u003cspan\u003eWeight:\u003c\/span\u003e\u003cspan\u003e 2.63 carats\u003c\/span\u003e\u003cspan\u003e\u003cbr\u003e \u003c\/span\u003e\u003cspan\u003eOrigin:\u003c\/span\u003e\u003cspan\u003e Tanzania\u003c\/span\u003e\u003cspan\u003e\u003cbr\u003e \u003c\/span\u003e\u003cspan\u003eColor:\u003c\/span\u003e\u003cspan\u003e Blue to Purple\u003c\/span\u003e\u003cspan\u003e\u003cbr\u003e \u003c\/span\u003e\u003cspan\u003eShape\/Cut:\u003c\/span\u003e\u003cspan\u003e Heart Faceted Cut\u003c\/span\u003e\u003cspan\u003e\u003cbr\u003e \u003c\/span\u003e\u003cspan\u003eMeasurements:\u003c\/span\u003e\u003cspan\u003e 8.30 × 9.01 × 5.44 mm\u003c\/span\u003e\u003cspan\u003e\u003cbr\u003e \u003c\/span\u003e\u003cspan\u003eHardness:\u003c\/span\u003e\u003cspan\u003e 8.0\u003c\/span\u003e\u003cspan\u003e\u003cbr\u003e \u003c\/span\u003e\u003cspan\u003eTreatment:\u003c\/span\u003e\u003cspan\u003e No Indication of Heat\u003c\/span\u003e\u003cspan\u003e\u003cbr\u003e \u003c\/span\u003e\u003cspan\u003eColor Change:\u003c\/span\u003e\u003cspan\u003e Observed under incandescent lighting\u003c\/span\u003e\u003cspan\u003e\u003cbr\u003e \u003c\/span\u003e\u003cspan\u003eCondition:\u003c\/span\u003e\u003cspan\u003e Loose Gemstone\u003c\/span\u003e\u003cspan\u003e\u003cbr\u003e \u003c\/span\u003e\u003cspan\u003ePrice:\u003c\/span\u003e\u003cspan\u003e \u003c\/span\u003e\u003cspan\u003e$6,000\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eAt \u003c\/span\u003e\u003cspan\u003e2.63 carats\u003c\/span\u003e\u003cspan\u003e, this is a substantial cobalt spinel combining an unusual heart cut with Tanzanian origin and documented blue-to-purple color change. It can stand alone as a collector specimen or become the centerpiece of a one-of-a-kind fine-jewelry design.\u003c\/span\u003e\u003c\/p\u003e","brand":"Rogue Valley Gem Exchange ","offers":[{"title":"Default Title","offer_id":52407582294312,"sku":null,"price":6000.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1007\/4059\/6008\/files\/IMG-6385.png?v=1789726802","url":"https:\/\/shop.roguevalleygemexchange.com\/products\/2-63-carats-natural-cobalt-blue-spinel-tanzania-blue-to-purple-color-change","provider":"Rogue Valley Gem Exchange ","version":"1.0","type":"link"}