CEN/TC 410 - Project Committee - Consumer confidence and nomenclature in the diamond industry

This document specifies a volumetric method for the determination of silver on a material considered homogeneous. The silver content of the sample lies preferably between (100 and 999,0) parts per thousand (‰) by mass. Fineness above 999,0 ‰ can be determined using a spectroscopy method by difference (e.g. ISO 15096).
This method is intended to be used as the reference method for the determination of fineness in alloys covered by ISO 9202.

This document specifies a gravimetric method for the determination of platinum on a material considered homogeneous. The platinum content of the sample lies preferably between 50 and 999 parts per thousand (‰) by mass. Fineness above 999 ‰ can be determined using a spectroscopy method by difference (e.g. ISO 15093).
This method is also intended to be used as one of the recommended methods for the determination of fineness in jewellery alloys covered by ISO 9202.

This document specifies a gravimetric method for the determination of palladium on a material considered homogeneous. The palladium content of the sample lies preferably between 50 and 999 parts per thousand (‰) by mass. Fineness above 999 ‰ can be determined using a spectroscopy method by difference (e.g. ISO 15093).
This method is also intended to be used as one of the recommended methods for the determination of fineness in jewellery alloys covered by ISO 9202.

This document specifies a cupellation method (fire assay) for the determination of gold on a material considered homogeneous. The gold content of the sample lies preferably between 100 and 999,5 parts per thousand (‰) by weight. Fineness above 999,5 ‰ can be determined using a spectroscopy method by difference (e.g. ISO 15093).
The procedure is applicable to most types of gold samples. Some modifications are indicated for specific cases (presence of large amount of base metals, platinum or palladium, silver). It is not compatible with the presence above trace levels of iridium, rhodium and ruthenium (more than 0,25 ‰ for the sum of all three elements).
This method is also intended to be used as the recommended method for the determination of fineness in jewellery alloys covered by ISO 9202.

This document describes an analytical procedure for the determination of platinum in platinum alloys with a nominal content up to 990 ‰ (parts per thousand), including alloys according to ISO 9202.

This document describes an analytical procedure for the determination of palladium in palladium alloys with a nominal content up to 990 ? (parts per thousand), including alloys according to ISO 9202.

ISO 18323:2015 specifies a set of permitted descriptors for the diamond industry and is specifically designed to be understood by the consumer. The Standard also includes a series of definitions which aim to provide further clarity for traders and maintain consumer confidence in the diamond industry as a whole.
ISO 18323:2015 will cover the nomenclature to be used by those involved in the buying and selling of diamonds, treated diamonds, synthetic diamonds, composite diamonds and imitations of diamonds.

This Technical Report specifies an acceptance sampling system of single sampling plans both for inspection by attributes and for inspection by variables. The attributes plans are of the accept-zero form, i.e. no lot is accepted if the sample from it contains one or more nonconforming articles. (For the purposes of this Technical Report, a nonconforming article is a precious metal article containing less than the nominal proportion by weight of the precious metal). The variables plans generally require smaller sample sizes than the attributes plans, but require the precious metal content of all the sampled articles to exceed the nominal content by at least a specified amount.
The objective of this Technical Report is to provide accept-zero schemes and procedures for assuring an upper limit to the long-term percentage of nonconforming precious metal articles in the market place (i.e. the percentage of articles reaching the market place that contain less than the nominal proportion of precious metal) by means of the lowest practicable sample sizes. The upper limit provided by this Technical Report is 1,47% nonconforming. The objective is achieved in three ways:
a)   the sample size reduces as the total number of articles accepted in all the lots since the last non-acceptance increases;
b)   if quality is consistently high, then subject to certain conditions it will be possible to switch from sampling by attributes to sampling by variables;
c)   under sampling by variables, further reductions in sample size may be achieved by switching from the unknown standard deviation method (the "s" method) to the known standard deviation method (the "s" method) if there is sufficient evidence that the process standard deviation is constant....

This European Standard specifies the precious metal content in solders suitable for use in the production of jewellery made of precious metal alloys.

Defines ring-size as inner circumference of the ring measured in mm.