{"title":"カラーチェンジサファイア｜光によって色を変える天然石","description":"\u003cp\u003eカラーチェンジサファイアは、自然が生み出す光学現象の中でも特に印象的なもののひとつです。光源によって、色の濃淡が変わるだけでなく、色そのものが実際に変わる天然コランダムです。自然光や蛍光灯の下では\u003ca href=\"\/ja\/collections\/blue-sapphire\"\u003eブルー\u003c\/a\u003e、ブルーグリーン、または\u003ca href=\"\/ja\/collections\/teal-sapphire-gemstones-unheated-blue-green-stones\"\u003eティール\u003c\/a\u003eに見え、白熱灯やろうそくの明かりの下に移すと、同じ石が\u003ca href=\"\/ja\/collections\/loose-purple-sapphires-unheated-ceylon-stones\"\u003eバイオレット\u003c\/a\u003e、パープル、または赤みを帯びたパープルに見えます。この変化は、結晶に含まれる微量のバナジウム（ときにクロムも）によるもので、昼光と白熱灯の光ではスペクトルの分布が異なるため、それぞれに対して異なるふるまいをします。色の変化が強く、はっきりしているほど、石は希少で評価も高くなります。\u003c\/p\u003e\n\n\u003ch2\u003eカラーチェンジサファイアとほかのサファイアの違い\u003c\/h2\u003e\n\n\u003cp\u003e一般的なサファイアでも、照明の環境によって明るさや濃さの印象が変わることはあります。カラーチェンジサファイアに起こるのは、それとは根本的に異なる現象で、濃淡ではなく色相そのものが変わります。ある光の下ではまぎれもなくブルー、別の光の下ではまぎれもなくパープルに見える石は、本当の意味でのカラーチェンジ現象を示しています。色の全体像がどのように分類されるかは、\u003ca href=\"\/ja\/blogs\/information-pages-complete-guide\/sapphire-colors-explained\"\u003eサファイアの色の解説\u003c\/a\u003eをご覧ください。最も近い現象石としては、\u003ca href=\"\/ja\/collections\/natural-cats-eye-chrysoberyl-chatoyancy-stones\"\u003eキャッツアイ・クリソベリルコレクション\u003c\/a\u003eもご覧ください。\u003c\/p\u003e\n\n\u003ch2\u003eカラーチェンジサファイアとアレキサンドライトの違い\u003c\/h2\u003e\n\n\u003cp\u003eアレキサンドライト（\u003ca href=\"\/ja\/collections\/natural-chrysoberyl-loose-stones-sri-lanka\"\u003eクリソベリル\u003c\/a\u003eのカラーチェンジの変種）は、最もよく知られたカラーチェンジの宝石で、昼光ではグリーン、白熱灯の下ではレッドに変わります。カラーチェンジサファイアは、一般にブルーからパープル、またはティールからバイオレットへと変化します。同等の品質で比べると、アレキサンドライトはカラーチェンジサファイアよりも1カラットあたりの価格が大幅に高くなります。どちらも天然の宝石であり、当店ではいずれもその現象を記載したGIAレポート付きでご用意しています。\u003c\/p\u003e\n\n\u003ch2\u003e処理と鑑別レポート\u003c\/h2\u003e\n\n\u003cp\u003e上質なカラーチェンジサファイアには非加熱のものが多く見られます。色の変化を生むバナジウムによる発色は、加熱処理によって良くなるものではないためです。処理の状態は全商品ページに明記しています。詳しくは\u003ca href=\"\/ja\/pages\/heated-vs-unheated\"\u003e加熱・非加熱ガイド\u003c\/a\u003eをご覧ください。GIAレポート付きのコレクター向けのカラーチェンジの石は、\u003ca href=\"\/ja\/collections\/collectors-and-investment-gemstones\"\u003eコレクター向けの宝石コレクション\u003c\/a\u003eをご覧ください。カラーチェンジサファイアにとってセイロンという産地がなぜ大切なのかは、\u003ca href=\"\/ja\/pages\/ceylon-sapphire-origin-guide\"\u003eセイロンサファイア産地ガイド\u003c\/a\u003eをご覧ください。\u003c\/p\u003e\n\n\u003ch2\u003eコレクターにとっての魅力\u003c\/h2\u003e\n\n\u003cp\u003e強いカラーチェンジを示すサファイア、つまりはっきりと異なる二つの色相の間で、完全に、劇的に色を変える石は、実際に希少で、コレクターに求められています。それぞれ単独でも収集の対象となる二つの色の系統（\u003ca href=\"\/ja\/collections\/blue-sapphire\"\u003eブルー\u003c\/a\u003eと\u003ca href=\"\/ja\/collections\/loose-purple-sapphires-unheated-ceylon-stones\"\u003eパープル\u003c\/a\u003e）を、ひとつの石の中にあわせ持っているのです。2カラットを超え、強い色の変化が記録され、GIAレポートが付いた上質な石は、コレクター向けの一石です。カラーチェンジは複数の光源の下で見てこそ正しく評価できるため、米国内のお客様は、一部の石を\u003ca href=\"\/ja\/collections\/try-before-you-buy-loose-gemstone\"\u003e試着プログラム（Try-On）\u003c\/a\u003eでお手元でご確認いただけます。米国外のお客様には、ご依頼に応じて、異なる光源の下でその石を撮影した動画を個別にお送りします。\u003c\/p\u003e\n\n\u003ch2\u003eよくあるご質問\u003c\/h2\u003e\n\n\u003ch3\u003eカラーチェンジサファイアは本物ですか？\u003c\/h3\u003e\n\u003cp\u003eはい。カラーチェンジサファイアは本物の天然の現象であり、処理や写真のトリックではありません。コランダムの結晶に含まれる微量のバナジウムが、昼光と白熱灯の光のスペクトルに対して異なるふるまいをするため、色相が変わります。一般に、昼光ではブルーやティール、白熱灯の下ではバイオレットやパープルに見えます。当店で販売する石はすべて正直に開示しており、上質な石にはその現象を記載したGIAレポートが付属します。\u003c\/p\u003e\n\n\u003ch3\u003eサファイアの色が変わる原因は？\u003c\/h3\u003e\n\u003cp\u003e原因は、結晶構造に含まれる微量のバナジウム（ときにクロムも）です。バナジウムは、光源のスペクトルの出方に応じて異なる波長の光を吸収します。そのため同じ石が、昼光でははっきりとブルーに、あたたかな白熱電球の下でははっきりとパープルに見えるのです。\u003c\/p\u003e\n\n\u003ch3\u003eカラーチェンジサファイアは希少ですか？\u003c\/h3\u003e\n\u003cp\u003eわずかな濃淡の変化ではなく、二つの異なる色相の間ではっきりと色を変える、強く完全なカラーチェンジは、サファイアでは実際に希少です。通常のブルーやピンクのサファイアよりも希少ですが、カラーチェンジのアレキサンドライトと比べれば、まだ入手しやすく手頃な価格です。\u003c\/p\u003e\n\n\u003cp\u003eご希望の条件に合わせた石のお探しは、\u003ca href=\"mailto:crescentgems@gmail.com\"\u003ecrescentgems@gmail.com\u003c\/a\u003eまでメールでお問い合わせください。14日間の返品保証。米国内送料無料。\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003e関連コレクション：\u003ca href=\"\/ja\/collections\/blue-sapphire\"\u003eブルーサファイア\u003c\/a\u003e - \u003ca href=\"\/ja\/collections\/loose-purple-sapphires-unheated-ceylon-stones\"\u003eパープルサファイア\u003c\/a\u003e - \u003ca href=\"\/ja\/collections\/teal-sapphire-gemstones-unheated-blue-green-stones\"\u003eティールサファイア\u003c\/a\u003e - \u003ca href=\"\/ja\/collections\/natural-cats-eye-chrysoberyl-chatoyancy-stones\"\u003eキャッツアイ・クリソベリル\u003c\/a\u003e - \u003ca href=\"\/ja\/collections\/natural-chrysoberyl-loose-stones-sri-lanka\"\u003eクリソベリル\u003c\/a\u003e - \u003ca href=\"\/ja\/collections\/collectors-and-investment-gemstones\"\u003eコレクター向けの宝石\u003c\/a\u003e - \u003ca href=\"\/ja\/collections\/all-sapphire-gemstones\"\u003eサファイア全体\u003c\/a\u003e\u003c\/em\u003e\u003c\/p\u003e","products":[{"product_id":"2-01-ct-color-change-sapphire-unheated-gia","title":"2.01 ct Natural Unheated Color-Change Sapphire – Cushion Cut | GIA Certified","description":"\u003cp\u003e2.01 carat rectangular cushion-cut color-change sapphire, natural and completely unheated, measuring 7.17 × 5.80 × 4.81 mm. The stone shifts from a saturated greenish-blue under daylight and fluorescent light to a clear purple under incandescent light — a well-defined two-color response that qualifies as a true color-change phenomenon. The shift is immediately visible when moving the stone between light sources. No heat treatment or any other enhancement of any kind; the color change is the stone's own natural property. Accompanied by GIA Report #1236949156 confirming natural origin, weight, dimensions, and unheated status.\u003c\/p\u003e\n\u003cdiv style=\"border: 2px solid #5b2c6f; border-radius: 10px; padding: 20px 24px; margin: 28px 0; background-color: #f9f5fc;\"\u003e\n\u003ch2 style=\"color: #4a235a; margin-top: 0;\"\u003e\u003cspan role=\"text\"\u003e\u003cstrong\u003eExpert Opinion\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\"What makes this stone worth stopping for is the phenomenon itself,\" says Ahmed Shareek, gemologist at Crescent Gems. \"This is a true, well-defined color-change sapphire — a saturated greenish-blue in daylight or fluorescent light that shifts to a clear purple under incandescent light. That's not a subtle drift in tone; it's two distinct colors in one stone, and it's completely natural and unheated. Genuine color-change corundum with this strong a response is something you don't come across often.\"\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003e\u003cspan role=\"text\"\u003e\u003cstrong\u003eRarity Analysis\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eTrue color-change phenomenon:\u003c\/strong\u003e Genuine color-change sapphire is rare in the gem market. The specific trace-element combination — typically vanadium — that produces a strong, well-defined two-color response in corundum under different light sources is uncommon; it's a much less frequent occurrence than the color-change effects seen in garnet or the classic alexandrite response in chrysoberyl.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStrength and clarity of the shift:\u003c\/strong\u003e This stone shows a well-defined two-color response, not a partial or muddy transition. A clean, unambiguous shift between greenish-blue and purple is itself a quality and rarity marker — many color-change stones on the market show only a faint or inconsistent shift.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnheated and untreated:\u003c\/strong\u003e This sapphire has never been heated. Heat treatment can damage or alter the trace-element structure responsible for color change, so natural material that displays this phenomenon without any enhancement is especially valued.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClarity:\u003c\/strong\u003e Minor inclusions under 10× in our own assessment — an honest, eye-clean grade rather than a flawless one. We note this plainly rather than overselling it.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIndependent documentation:\u003c\/strong\u003e Accompanied by GIA Report #1236949156, confirming natural origin, weight, dimensions, and unheated status from an independent laboratory.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCombined effect:\u003c\/strong\u003e A genuine, strongly defined color-change phenomenon in an unheated natural sapphire, backed by GIA documentation, places this stone in a distinctly small category of gemstones — most sapphires show no color-change effect at all, and those that do rarely display it this clearly.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003e\u003cspan role=\"text\"\u003e\u003cstrong\u003eBuying Guidance\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003eView the stone under both daylight (or fluorescent) light and incandescent light before buying. The entire value of this gem lies in the shift itself, so confirm you like both the greenish-blue daylight color and the purple incandescent color — not just one of the two.\u003c\/li\u003e\n\u003cli\u003eVerify unheated, natural color-change status through an independent lab report rather than taking a listing's word for it. Color-change effects can sometimes be imitated, induced, or enhanced in lesser stones, so third-party confirmation matters here more than with a single-color sapphire.\u003c\/li\u003e\n\u003cli\u003eKeep in mind the origin listed, Madagascar, is seller-stated rather than explicitly confirmed on the GIA report, which documents natural origin, weight, dimensions, and unheated status but does not certify country of origin.\u003c\/li\u003e\n\u003cli\u003eJudge clarity honestly: in our own assessment this stone has minor inclusions under 10× — eye-clean beauty, not a flawless stone — and that distinction should factor into your expectations at this price point.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTry Before You Buy:\u003c\/strong\u003e Because this stone's entire appeal rests on the light-to-light transformation, we recommend examining it in person or under multiple lighting setups whenever possible, so you can be certain both color states work for you before committing.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003e\u003cspan role=\"text\"\u003e\u003cstrong\u003eLearn More About This Gemstone\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/ja\/blogs\/information-pages-complete-guide\/color-change-sapphire-guide\"\u003eColor-Change Sapphire Guide\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/ja\/blogs\/information-pages-complete-guide\/what-is-a-gia-sapphire-report-and-how-do-you-read-one\"\u003eWhat Is a GIA Sapphire Report and How Do You Read One?\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/ja\/blogs\/information-pages-complete-guide\/how-to-commission-custom-sapphire-ring\"\u003eCustom Sapphire Rings — The Complete Guide\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/ja\/blogs\/information-pages-complete-guide\/sapphire-buying-guide\"\u003eThe Ultimate Guide to Buying Natural Loose Sapphires\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/ja\/blogs\/information-pages-complete-guide\/what-is-an-unheated-sapphire\"\u003eWhat Is an Unheated Sapphire? The Complete Buyer's Guide\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/ja\/blogs\/information-pages-complete-guide\/madagascar-sapphire-guide\"\u003eMadagascar Sapphire — The Modern Origin That Rivals Ceylon\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/ja\/blogs\/information-pages-complete-guide\/cushion-cut-sapphire-guide\"\u003eCushion Cut Sapphire — The Complete Guide to the Vintage Shape That Deepens Color\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"border: 2px solid #5b2c6f; border-radius: 10px; padding: 20px 24px; margin: 28px 0; background-color: #f9f5fc;\"\u003e\n\u003ch2 style=\"margin-top: 0; margin-bottom: 14px; color: #4a235a;\"\u003eGemstone Data — At a Glance\u003c\/h2\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; font-size: 0.95em;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600; width: 42%;\"\u003eItem #\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eCG8355\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eCarat Weight\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003e2.01 ct\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eSpecies \/ Variety\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eNatural Color-Change Sapphire (Corundum)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eShape \/ Cut\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eRectangular Cushion, Mixed Brilliant\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eDimensions\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003e7.17 × 5.80 × 4.81 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eColor \/ Intensity\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eSaturated greenish-blue (daylight\/fluorescent) to purple (incandescent)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003ePhenomenon\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eTrue color-change (greenish-blue to purple)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eTreatment\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eNone — unheated and untreated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eOrigin\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eMadagascar — seller-stated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eClarity\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eMinor inclusions under 10× — our own assessment; GIA colored-stone reports carry no clarity grade\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eTransparency\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eTransparent\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eHardness\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003e9 (Mohs)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; font-weight: 600;\"\u003eCertification\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px;\"\u003eGIA Report #1236949156\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003e\u003cstrong\u003eFeatures\u003c\/strong\u003e\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003eSKU: CG8355\u003c\/li\u003e\n\u003cli\u003eCarat Weight: 2.01 carats\u003c\/li\u003e\n\u003cli\u003eVariety: Color-Change Sapphire\u003c\/li\u003e\n\u003cli\u003eShape: Rectangular Cushion\u003c\/li\u003e\n\u003cli\u003eCutting Style: Mixed Brilliant (brilliant crown, modified step cut pavilion)\u003c\/li\u003e\n\u003cli\u003eDimensions: 7.17 × 5.80 × 4.81 mm\u003c\/li\u003e\n\u003cli\u003eGem Type: Natural Color-Change Sapphire\u003c\/li\u003e\n\u003cli\u003eOrigin: Madagascar\u003c\/li\u003e\n\u003cli\u003eTreatment: None — unheated and untreated (no indications of heating)\u003c\/li\u003e\n\u003cli\u003eColor: Greenish-blue (daylight \/ fluorescent) to purple (incandescent)\u003c\/li\u003e\n\u003cli\u003eTransparency: Transparent\u003c\/li\u003e\n\u003cli\u003eClarity: Minor inclusions under 10× — our own assessment, not a GIA grade\u003c\/li\u003e\n\u003cli\u003eCertification: GIA Report #1236949156\u003c\/li\u003e\n\u003cli\u003eHardness: 9 on the Mohs scale\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003e\u003cstrong\u003eCare\u003c\/strong\u003e\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003eClean with lukewarm water and mild soap using a soft brush\u003c\/li\u003e\n\u003cli\u003eStore separately to avoid surface contact\u003c\/li\u003e\n\u003cli\u003eRemove before heavy physical activity\u003c\/li\u003e\n\u003cli\u003eAvoid ultrasonic or steam cleaners\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003e\u003cstrong\u003eOne of a Kind\u003c\/strong\u003e\u003c\/h2\u003e\n\n\u003cp\u003eThis is a single natural gemstone, not a manufactured or lab-created replica — no two sapphires form with identical color, inclusions, and internal character, and true color-change stones like this one are especially uncommon. Once this stone sells, it's gone; there is no duplicate. What you see documented on the GIA report is the exact, individual stone you receive.\u003c\/p\u003e\n\n\u003ch2\u003e\u003cstrong\u003eWhat’s included with this Color-Change Sapphire\u003c\/strong\u003e\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003eGIA Report #1236949156\u003c\/li\u003e\n\u003cli\u003eGemstone packed in a gem sleeve\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Crescent Gems","offers":[{"title":"Default Title","offer_id":42798903623747,"sku":"CG8355","price":2211.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0658\/8982\/8931\/files\/1112023001_96c376e1-d3a5-470f-affd-600dfa3a10c7.jpg?v=1778308039"},{"product_id":"1-03-ct-natural-untreated-color-change-sapphire","title":"1.03 ct Natural Unheated Color-Change Sapphire – Emerald Cut | Sri Lanka (Ceylon)","description":"\u003cp\u003eA natural 1.03 ct Emerald Cut Color-Change Sapphire, from Sri Lanka (Ceylon), completely unheated and certified by AGCL (Arctic Gem Certification \u0026amp; Laboratory), Report #M263506. Color-change sapphires shift hue between lighting environments — this stone displays a distinctly different color under daylight versus incandescent light (green to reddish purple, per the AGCL report), a phenomenon caused by trace vanadium in the crystal that absorbs different wavelengths under different spectral distributions. At just over 1 carat from Ceylon, unheated, this is a well-specified example of one of the most unusual optical phenomena in natural gemstones.\u003c\/p\u003e\n\n\u003cdiv style=\"border: 2px solid #5b2c6f; border-radius: 10px; padding: 20px 24px; margin: 28px 0; background-color: #f9f5fc;\"\u003e\n\u003ch2 style=\"margin-top: 0; margin-bottom: 12px; color: #4a235a;\"\u003eExpert Opinion\u003c\/h2\u003e\n\u003cp style=\"font-weight: 600; margin-bottom: 6px;\"\u003e\u003ca href=\"\/ja\/pages\/ahmed-shareek-about-the-owner\" style=\"color: #4a235a; text-decoration: underline;\"\u003eAhmed Shareek\u003c\/a\u003e's Assessment\u003c\/p\u003e\n\u003cp style=\"font-style: italic; margin-bottom: 0;\"\u003e\"Genuine, lab-documented color-change sapphire is one of the rarest phenomena in the sapphire family — in my experience, on par with star sapphire for scarcity, because the vanadium chemistry needed to produce a clean shift between daylight and incandescent light rarely lines up this well. This stone's AGCL-documented change from green to reddish purple is unusually well-defined, and the fact that it's unheated matters even more here, since heat treatment is known to weaken or destroy the color-change effect entirely.\"\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003e\u003cspan role=\"text\"\u003e\u003cstrong\u003eRarity Analysis\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\n\u003cp\u003eColor-change sapphire is one of the rarest phenomena in the sapphire family, alongside star sapphire — most sapphire production never yields a stone that shifts convincingly between light sources, and this 1.03 ct stone combines that phenomenon with unheated status and a stated Ceylon origin.\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePhenomenon:\u003c\/strong\u003e This stone shows a genuine, AGCL-documented color change — green under daylight versus reddish purple under incandescent light. The effect is caused by trace vanadium in the crystal structure, which absorbs different wavelengths depending on the spectral makeup of the light source. Only a small fraction of sapphire crystals contain vanadium in the concentration and balance needed to produce a clean, visible shift, which is why color-change sapphire is considered one of the rarest sapphire phenomena alongside asterism (star sapphire).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e Green (daylight) to Reddish Purple (incandescent) — a well-defined, clearly visible shift rather than a subtle tone change.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize:\u003c\/strong\u003e 1.03 carats — above the 1-carat threshold most buyers look for in a center stone, in a size where the color shift remains easy to see with the naked eye.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTreatment:\u003c\/strong\u003e Unheated. This matters more for a color-change stone than for an ordinary sapphire — heat treatment can weaken or destroy the color-change effect entirely, so an unheated stone with a strong, documented shift is harder to find than an unheated stone in a standard color.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClarity:\u003c\/strong\u003e This stone has visible inclusions — our own assessment, not a lab grade. The color shift is judged separately from clarity, but view the stone in hand if clarity matters to you.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocumentation:\u003c\/strong\u003e AGCL Report #M263506 confirms no indication of heating; origin is stated as Sri Lanka (Ceylon).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCombined effect:\u003c\/strong\u003e A genuine color-change phenomenon, unheated status, Ceylon origin, and independent lab documentation rarely converge in a single stone at this size — each factor narrows the pool of qualifying stones further.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003e\u003cspan role=\"text\"\u003e\u003cstrong\u003eBuying Guidance\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\n\u003cp\u003eColor-change sapphire is judged differently than a single-color stone — the quality of the shift itself, not just hue or clarity, is what separates a strong stone from an average one. A few things are worth checking before you buy.\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eView it in multiple light sources:\u003c\/strong\u003e This is essential for a color-change stone — ask for photos or video showing the stone under both daylight\/fluorescent light and incandescent light so you can judge the strength and cleanliness of the shift for yourself.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConfirm the lab report matches the stone:\u003c\/strong\u003e Check that the AGCL report number, weight, and measurements correspond exactly to the stone you're purchasing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAsk about the degree of color change:\u003c\/strong\u003e Not all color-change sapphires shift equally strongly — some show a dramatic change, others a subtler one. Ask for a direct description of how pronounced the change is on this specific stone.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConsider the setting:\u003c\/strong\u003e An open setting that lets light reach the pavilion will show the color-change effect more clearly than a setting that blocks light from certain angles.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTry Before You Buy:\u003c\/strong\u003e Where possible, view the stone in person or request additional imaging under controlled light sources before committing — a phenomenon like this is best judged firsthand.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003e\u003cspan role=\"text\"\u003e\u003cstrong\u003eLearn More About This Gemstone\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/ja\/blogs\/information-pages-complete-guide\/color-change-sapphire-guide\"\u003eColor-Change Sapphire — The Phenomenon Stone That Shifts Before Your Eyes\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/ja\/blogs\/information-pages-complete-guide\/what-is-an-unheated-sapphire\"\u003eWhat Is an Unheated Sapphire? The Complete Buyer's Guide\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/ja\/blogs\/information-pages-complete-guide\/natural-sapphires-online-premium-gemstones\"\u003eHow to Buy Natural Sapphires Online: What Certification Actually Tells You\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/ja\/blogs\/information-pages-complete-guide\/how-to-commission-custom-sapphire-ring\"\u003eHow to Commission a Custom Ring — From Loose Stone to Finished Piece\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/ja\/blogs\/information-pages-complete-guide\/sapphire-buying-guide\"\u003eThe Ultimate Guide to Buying Natural Loose Sapphires\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"border: 2px solid #5b2c6f; border-radius: 10px; padding: 20px 24px; margin: 28px 0; background-color: #f9f5fc;\"\u003e\n\u003ch2 style=\"margin-top: 0; margin-bottom: 14px; color: #4a235a;\"\u003eGemstone Data — At a Glance\u003c\/h2\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; font-size: 0.95em;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600; width: 42%;\"\u003eItem #\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eCG8412\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eCarat Weight\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003e1.03 ct\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eSpecies \/ Variety\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eNatural Color-Change Sapphire (Corundum)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eShape \/ Cut\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eEmerald Cut\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eDimensions\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003e5.80 x 4.86 x 3.72 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eColor \/ Intensity\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eGreen (daylight) to Reddish Purple (incandescent), per AGCL report\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003ePhenomenon\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eColor Change — green (daylight) to reddish purple (incandescent), per AGCL Report #M263506\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eTreatment\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eUnheated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eOrigin\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eSri Lanka (Ceylon)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eClarity\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eVisible inclusions (our own assessment, not a lab grade)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eTransparency\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003eTransparent\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee; font-weight: 600;\"\u003eHardness\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px; border-bottom: 1px solid #e5d9ee;\"\u003e9 (Mohs)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 6px 8px; font-weight: 600;\"\u003eCertification\u003c\/td\u003e\n\u003ctd style=\"padding: 6px 8px;\"\u003eAGCL Report #M263506\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003e\u003cspan role=\"text\"\u003e\u003cstrong\u003eWhy Choose this 1.03 ct Unheated Ceylon Color-Change Sapphire?\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\n\u003cp\u003eColor-change sapphire in unheated quality above 1 carat from Ceylon is uncommon — the combination of the phenomenon, the treatment status, and the origin in a single stone represents a meaningful convergence of collectible attributes. The Emerald Cut at this weight is a practical format for showing the color shift in both earring\/pendant and ring settings.\u003c\/p\u003e\n\n\u003ch2\u003e\u003cspan role=\"text\"\u003e\u003cstrong\u003eKey Benefits of this 1.03 ct Emerald Cut Color-Change Sapphire\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnheated Ceylon Origin\u003c\/strong\u003e\u003cbr\u003eNo thermal treatment — AGCL Report #M263506 confirms no indication of heating. Heat can diminish the shift.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGenuine Color-Change Phenomenon\u003c\/strong\u003e\u003cbr\u003eThe stone reads a distinctly different hue under daylight versus incandescent light — a natural optical effect.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAbove-1-Carat Size\u003c\/strong\u003e\u003cbr\u003e1.03 carats — the threshold for center stone use in most standard engagement and pendant settings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePhenomenon Accessible to View\u003c\/strong\u003e\u003cbr\u003eAt this size, the color shift is clearly visible with the naked eye under different light sources.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDurable for Daily Wear\u003c\/strong\u003e\u003cbr\u003eCorundum at Mohs 9, second only to diamond.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003e\u003cspan role=\"text\"\u003e\u003cstrong\u003eFeatures\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003eCarat Weight: 1.03 Carats\u003c\/li\u003e\n\u003cli\u003eGem Type: Natural Color-Change Sapphire\u003c\/li\u003e\n\u003cli\u003eVariety: Color-Change Sapphire\u003c\/li\u003e\n\u003cli\u003eShape: Octagonal\u003c\/li\u003e\n\u003cli\u003eCut Style: Emerald Cut\u003c\/li\u003e\n\u003cli\u003eDimensions: 5.80 x 4.86 x 3.72 mm\u003c\/li\u003e\n\u003cli\u003eOrigin: Sri Lanka (Ceylon)\u003c\/li\u003e\n\u003cli\u003eTreatment: Unheated\u003c\/li\u003e\n\u003cli\u003eColor: Green to Reddish Purple (color-change)\u003c\/li\u003e\n\u003cli\u003eClarity: Visible inclusions (our own assessment, not a lab grade)\u003c\/li\u003e\n\u003cli\u003eHardness: 9 on the Mohs scale\u003c\/li\u003e\n\u003cli\u003eCertification: AGCL Gemstone Report #M263506\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThis 1.03 ct Emerald Cut Color-Change Sapphire has been hand-selected for the clarity and completeness of its color shift — the quality that distinguishes a strong color-change from a mere tone variation.\u003c\/p\u003e\n\n\u003ch2\u003e\u003cspan role=\"text\"\u003e\u003cstrong\u003eOne of a Kind\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\n\u003cp\u003eThis is a single natural gemstone, not a manufactured or lab-created replica — no two color-change sapphires form with identical color behavior, clarity, and internal character. Once this stone sells, it's gone; there is no duplicate. What you see documented on the AGCL report is the exact, individual stone you receive.\u003c\/p\u003e\n\n\u003ch2\u003e\u003cspan role=\"text\"\u003e\u003cstrong\u003eCare\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\n\u003cp\u003eSapphire is exceptionally durable (Mohs 9), but a few habits keep it looking its best. Clean with warm water, mild soap, and a soft brush; avoid ultrasonic or steam cleaners if the stone is set alongside softer or treatment-sensitive materials. Store separately from other jewelry to prevent surface scratches to softer pieces, and remove the stone before swimming, exercising, or household chemical exposure. As an unheated stone, no thermal treatment stabilizes the color — normal wear is fine, but avoid sudden extreme temperature changes.\u003c\/p\u003e\n\n\u003ch2\u003e\u003cspan role=\"text\"\u003e\u003cstrong\u003eWhy Customers Love This Gemstone\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnheated Phenomenon:\u003c\/strong\u003e The color-change is entirely natural — heat can weaken this optical effect.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLiving Color:\u003c\/strong\u003e A stone that reads differently in every light source — inherently dynamic.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCeylon Origin:\u003c\/strong\u003e The primary source for natural color-change sapphire at the fine commercial level.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTrusted Source:\u003c\/strong\u003e Treatment disclosed honestly and independently certified by AGCL (Report #M263506).\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eOwning this 1.03 ct unheated Ceylon color-change sapphire means choosing a stone whose most distinctive quality — its shift between two colors — is entirely natural and unaltered.\u003c\/p\u003e\n\n\u003ch2\u003e\u003cspan role=\"text\"\u003e\u003cstrong\u003ePerfect Uses for this 1.03 ct Color-Change Sapphire\u003c\/strong\u003e\u003c\/span\u003e\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003eDistinctive engagement ring center stone\u003c\/li\u003e\n\u003cli\u003eCollector centerpiece for phenomenon gemstones\u003c\/li\u003e\n\u003cli\u003eStatement pendant — phenomenon visible in any light\u003c\/li\u003e\n\u003cli\u003eConversation piece for fine jewelry enthusiasts\u003c\/li\u003e\n\u003cli\u003eInvestment in documented natural color-change material\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Crescent Gems","offers":[{"title":"Default Title","offer_id":43031904518211,"sku":"CG8412","price":824.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0658\/8982\/8931\/files\/1112023001_0b7c91d9-1004-4ae0-9c8f-6ce83422f6d3.jpg?v=1778308074"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0658\/8982\/8931\/collections\/stone_CG8305_image-2.jpg?v=1784371249","url":"https:\/\/crescentgems.com\/ja\/collections\/color-change-sapphire.oembed","provider":"Crescent Gems","version":"1.0","type":"link"}