Our certificates

Our certificates

With every purchase of a piece of jewellery from our assortment you receive a document named as certificate. This contains all information of the jewellery description about the used materials, the age and the origin, as well as „technical data“, such as mass and weight.

Furthermore the main picture of the article description is to be found in it and the address data entered by you. Therefore this document is a purchase document and a RHEINFRANK Jewellery certificate in one.

Determination of precious stones

We value the quality and characteristics of our diamonds and coloured gemstones with the high expert knowledge from more than 15 years of experience in antique jewellery trade.

An exact classification of set gemstones, as they exist here without exception, is not possible though. In case of having a certificate concerning a precious stone of a stone-examining institute, this is unambiguously stated in the article description. With deepest conviction we are against a general classification by an institute. Since this would mean, our antique jewellery would have to be deconstructed!

We consider our pieces of jewellery as unique pieces of art. The setting of precious stones would sustainably interfere the work of the goldsmith or the jeweller.

Size, weight and grinding form

We determine the weight (is given in terms of ct.) and the size of a precious stone
in the existing, thus in a set state. Our measurements are very precise, nevertheless, are made inevitably as approximate data. With the help of visible and measurable qualities, as well as the present grindings, our calculations are so understandably exact, that we publish them with the jewellery description and confirm in writing in case of purchase.

The grinding form is to be recognised unquestionably also in the set state of the stones.  Whether the precisely defined proportions were fulfilled by the grinder, nevertheless, does not belong to the checkable and therefore also not to the valuable data. Concerning this, we urgently ask for giving us your apparent impression when making the personal assessment. Only gemstones of highest grinding quality are set in the antique pieces of jewellery offered by us.

Colour and purity of diamonds

The apparent colour impression of a set diamond is strongly influenced by the
colour of the material, in which it is set. Consequently, it had to be set to make an exact determination. For our real antique jewellery from 3 centuries this is not possible! These circumstances also concern the determination of clarity (purity degree) of set diamonds.

Up to to a certain degree colour and purity of a diamond are understandable for us as experienced antique jewellery specialists, partly with the help of our master goldsmith. This information is not binding and therefore, no part of our jewellery descriptions. We also call at this point on our customers and jewellery enthusiasts, to not value more the gemmological data of a precious stone than the holistic impression of a piece of jewellery.

Without exception every precious stone, which is set in our antique and real vintage pieces of jewellery, is of excellent jewellery quality. The extremely slight differences, which influence the graduation by definition are apparently almost not to be seen.