Based on Holger Aulenbach´s experience in trading several thousand carats of certified an none certified diamonds, he has concluded that only the following three certification institutes should be considered when evaluating diamonds. However, this is not all. Additional factors are taken into account for the certificates he recognize. Each diamond and jewel is taken under personal examine by Holger Aulenbach. In rare cases he might not even accept or agree with the assessment result of IGI or GIA certificates and instead subject them to an additional review by the Hoge Raad voor Diamant (HRD). Occasionally, he optains cut diamonds that do not possess any of the aforementioned certificates but have other assessments, in addition to his personal evaluations, that he fully recognizes. This could, for example, be the rating of the mining company.
