About us

First private and independent gemmological laboratory

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In a more and more complex market where synthetic diamonds and various treatments are increasingly available, the identification of your gems by LLG will reassure you about their precise nature. Through the use of advanced technology and state of the art analysis equipment, LLG provides both professionals and individuals with the appropriate support to secure their investments.

An expert team at your service

Our team is composed of gemmologists for whom each stone is a world on its own.

University graduates and/or scientists who have been trained in some of the best laboratories worldwide (including GIA New York and Gem-A), they represent today’s modern and rigorous gemmology which knows how to take advantage of technological advances. The diversity of their experience, as well as their complementary skills allows them to cover all of our customers’ expectations.

Our values


As an independent laboratory, our mission is to identify gemstones according to well-defined standards, whilst improving the traceability of diamonds worldwide (Gemprint® technology).


Thanks to the roadmaps of our experts, our modern equipment and rigorous grading protocols, our customers can count on reliable results, delivered in a short time frame.


Highly secure, our facilities and working methods guarantee absolute discretion to our customers about their identity and the characteristics of their gems.


LLG meets the most stringent international requirements in terms of grading methods, and aims at building long-lasting relationships with our customers on a daily basis.

Phillips Square, the historical diamond district in Montreal

Located in the heart of Montreal, two steps away from Phillips Square, LLG responds to the growing demand from both professionals and individuals who wish to have their stones rapidly analyzed and in full confidentiality.

The square was named after Thomas Phillips, a building contractor and city councillor who owned the square in the 19th century. For quite a while, it was a wealthy residential area. The first shops appeared at the end of the 19th century, these included: Alfred Joyce in 1878, Morgan’s in 1891 (bought by La Baie in 1960) and Henri Birks and Sons in 1894. Following the opening of Birks, many diamond dealers, lapidaries and jewellers decided to open shops on the square and in nearby Cathcart street.

Des équipements de pointe uniques au Canada

LLG est équipé de deux salles blanches et des instruments les plus sophistiqués disponibles dans l’industrie, parmi lesquels :

La technologie Gemprint®

Utilisé par le FBI et le gouvernement canadien, Gemprint® est un instrument d’identification non invasif pour les pierres à haut degré de brillance et de transparence comme le diamant. Il tire parti de la technologie laser pour révéler l’empreinte lumineuse d’une gemme – qui est unique, comme une empreinte digitale. Chaque empreinte lumineuse est enregistrée dans une base de données mondiale afin de permettre une meilleure traçabilité des diamants. LLG est le premier laboratoire privé canadien à disposer de cet équipement novateur.

La technologie AMS2

Dernier né de la gamme d’instruments mis au point par De Beers, l’AMS2 permet d’identifier les mêlées de diamants. Avec une capacité d’environ 3600 pierres par heure, cet appareil peut analyser une grande diversité de formes de gemmes, même de taille millimétrique.

Autres équipements de pointe

Diamond Sure, Diamond View : la technologie UV de cet instrument permet d’identifier si le diamant est naturel en révélant les structures de croissance de la pierre.

Alpha II Diamond Analyser : la technologie infrarouge FT-IR permet d’analyser la composition chimique et la structure des diamants bruts ou taillés, peu importent leur taille et leur couleur, et de déterminer le type pour le diamant naturel (avec Azote ou sans Azote).