Your
gemstones
unveiled

  • Asteriated luminescent structure in a rough diamond
    Asteriated luminescent structure in a rough diamond
  • Liquid film in a peridot from the Supat mine, Kohistan, Pakistan
    Liquid film in a peridot from the Supat mine, Kohistan, Pakistan
  • Rose Channels in a Sapphire in the Umba Valley, Tanzania
    Rose Channels in a Sapphire in the Umba Valley, Tanzania
  • Two-tone luminescent structure in a rough diamond
    Two-tone luminescent structure in a rough diamond
  • Structure of a pearl of Pinna nobilis
    Structure of a pearl of Pinna nobilis
  • Feldspath inclusions in a sapphire from Tirymena, Madagascar
    Feldspath inclusions in a sapphire from Tirymena, Madagascar

Your
gemstones
unveiled

Asteriated luminescent structure in a rough diamond

Our services

Diamond services

We provide grading and analytical reports for both loose and mounted diamonds.

Discover

Coloured gemstone services

With more than 20 years of expertise, we can guide you through the world of gemstones by uncovering authenticity, treatment, and geographical origin.

Discover

Exclusive services

What makes us special besides our expertise?
Our exclusive services.

Discover

GGTL laboratories

Welcome to GGTL Laboratories. An experienced laboratory like no other where science, technology, and research ally to give you the best of gemmology.

Latest news

Atelier de gemmologie à la Haute Ecole Arc - HES-SO : Retour sur un événement enrichissant
Insight

Gemology workshop at Haute Ecole Arc - HES-SO: A look back at an enriching event

Read
Natural glass inclusions in the form of atolls in an unheated ruby
Micrographs

Natural glass inclusions in the form of atolls in an unheated ruby

Read
Formation of synthetic spinel in a heated sapphire
Micrographs

Formation of synthetic spinel in a heated sapphire

Read

Happy to hear from you

Didn’t find what you were looking for? Have a question about our expertise or services? Do not hesitate to contact us and we will get back to you.

Contact us