An Alexandrite and Diamond RingThe cushion-shaped alexandrite, weighing 2.69 carats, between oval-cut diamond shoulders, within a brilliant-cut diamond surround, diamonds approximately 1.00 carat total, ring size 6½注脚Accompanied by an AGL (American Gemological Laboratories) report stating that the natural chrysoberyl alexandrite changes from Blue-Green (fluorescent light) to Reddish Pink (incandescent light) colour, has no indications of clarity enhancement and originates from Brazil. Report number 8088281, dated 24 September 2018.Accompanied by a GRS report stating that the natural alexandrite chrysoberyl changes from Yellowish-Green (daylight) to Purplish-Red (incandescent light) colour, has no indications of treatment and originates from Brazil. Report number GRS2017-118565, dated 20 November 2017.2.69克拉天然無經處理巴西亞歷山大石配鑽石戒指鑽石共重約1.00克拉,戒指尺寸6½,附AGL及GRS證書AlexandriteFirst discovered in the Ural Mountains in Western Russia in the 1830s, this exceptionally-rare colour-changing stone was named in honour of the future Czar of Russia Alexander II, and is now found in other geographical locations including Brazil, Sri Lanka and East Africa. Judged on the richness of the colour-change, the finest examples are unheated and turn green to bluish-green in natural daylight and a striking red to purplish-red in incandescent light.亞歷山大石這種極為珍稀的變色寶石最先在1830年代於俄羅斯西部的烏拉爾山脈中被發現，當時以紀念未來的俄羅斯亞歷山大二世沙皇而命名，現於巴西，斯里蘭卡和東非等其他地區也有出產。 從色彩變化的豐富程度來看，最優質的是寶石沒有經過加熱，颜 色在自然光下是綠色到藍綠色，而在白熾燈光下是紅色到紫紅色。