Hartmann’s provides jewellery certification with the sale of every piece of diamond jewellery. If the piece is set with a diamond above 0.40ct, a diamond grading report will also be provided from one of the two independent diamond grading institutes:

 GIA in the USA or HRD in Belgium.


 Hartmann's works with GIA and HRD.

GIA (Gemological Institute of America) The Gemological Institute of America, or GIA, is a nonprofit institution dedicated to research and education in gemmology and jewellery art.

Founded in 1931, GIA’s mission is to protect all buyers and sellers of gemstones by setting and maintaining the standards used to evaluate gemstone quality.




HRD (Hoge Raad Voor Diamant), Antwerp Hoge Raad Voor Diamant (HRD), or ‘Diamond High Council’, is a nonprofit institution established in Antwerp in 1973 as the GIA’s European counterpart.

In addition to monitoring the import and export of more than half the world’s loose diamond supply, HRD issues recognised grading reports for diamonds and precious stones based on internationally accepted standards.

Hartmann's has several employees who are trained and certified diamond graders from the Belgian HRD.

The shop’s opening hours

View detailed opening hours
  • Monday 10:00 to 5:30
  • Tuesday 10:00 to 5:30
  • Wednesday 10:00 to 5:30
  • Thursday and Friday 10:00 to 5:30
  • Saturday 10:00 to 2:00

Request a call back

Visit our shop and get expert advice from one of our employees.

If you wish to be contacted by a sales representative, please complete the form below.