The GIA certificate is a certificate issued by the GIA, the Gemological Institute of America. Now widely adopted, this international diamond grading system for diamond cut, carat, justice and colour was created in 1953 by Richard T. Liddicoat, Chairman of Grease A's Board of Directors. After the establishment of this system of completeness and consistency of results, many people asked the Gemological Institute of America to develop a set of submission procedures. Therefore, in 1955, the Gemological Institute of America issued the first diamond grading report, which is what we call it. diamond certificate. In addition to issuing certificates for natural diamonds, GIA also provides services for identifying and issuing certificates for lab grown diamonds.
IGI
IGI certificates are issued by the International Gemological Institute.
The International Gemological Institute was established in Belgium in 1975 to conduct private diamond appraisals for a few diamond families. After these high-quality diamonds were sold to European royal families, IGI's reputation gradually increased. Even the royal families of the Middle East sent their jewellery to IGI for appraisal. IGI identifies most lab grown diamonds, and its certificate standards are roughly the same as GIA. In terms of cut, it is one more level than Ideal, GIA's top "Excellent" cut grade and Ideal is the top cut grade.
EGL
歐洲寶石鑒定(European Gemological Laboratory)所是鑽石分級的先鋒組織。於1974年成立的EGL多年來鑒定了大部份以色列出口的鑽石及寶石。EGL在世界各地均設有辦事處，2009年11月，EGL亞洲實驗室在中國上海設立華東區業務聯繫中心在中國市場變得普及。加上EGL鑒定服務價格相對便宜，因而得到小型鑽石零售商的青睞。EGL證書的結構與傳統的GIA報告相似，但標準卻較GIA寬鬆，亦因此導致EGL的信譽受質疑。
HRD
比利時鑽石高階層(Hoge Raad voor Diamant)，成立於鑽石名都安特衛普，安特衛普的鉆石業有約1500年的歷史。全球超過50%的寶石級鑽石從這裡銷售往世界各地。 HRD的實驗室為國際標準化認證的寶石實驗室（ISO。/IEC17025）。 HRD證書使用較多描述性語言，例如鑽石顏色的不用D、E、F等劃分，而是用如“WHITE”“SLIGHTLY TINTED WHITE”等短語，且N以下色級就不再區分；另外，HRD有一種針對1克拉以下鑽石的快捷“鑽石鑒定證書”，相對其“鑽石證書”，內容信息都比較簡略。HRD鑒定過程嚴謹，採用不記名原則，以確保鑒定結果的客觀性。 HRD證書在歐洲具有一定的地位，被很多在比利時和荷蘭的鑽石分銷巨頭和買方。
Read More:
