Grunberger Diamonds traces its roots to Antwerp, Belgium’s diamond district, where craftsmanship and trade shaped the global jewelry market. The company began with Samuel Grunberger in the 1930s, laying the foundation for a multigenerational family business known for precision-cut small stones.
Grunberger Diamonds Japan
By the 1950s, it employed more than 1,000 workers and gained recognition at major industry events. Samuel’s son, Marcel, led the company through the 1960s as it scaled up production, strengthened quality control and earned national honors in Belgium for its contribution to the diamond sector.
The group’s expansion reflected not only growth in volume, but also a widening geographic footprint. In the 1980s and 1990s, its facilities had moved beyond Belgium to Thailand and Vietnam, and the next generation established offices in New York in 1997 and Hong Kong in 2009.
Today, Grunberger Diamonds operates across global markets, including Japan, where President Simon Grunberger says the business culture rewards consistency and long-term commitment.
“Japan feels like home. It isn’t easy to gain the trust of Japanese people, but once you show your commitment and dedication, the relationships that come out of it are like the roots of a tree — deep and wide,” he said.
A centerpiece of the company’s identity is the Grunberger precision cut, a method designed for ideal proportions and optical symmetry, producing melee diamonds with strong fire and the hearts and arrows pattern.
As Belgium and Japan mark 160 years of relations in 2026, Grunberger calls it a reminder of sustained collaboration. “This marks a very important anniversary of collaboration and long-standing relationship,” he said.
“Japan feels like home. It isn’t easy to gain the trust of Japanese people, but once you show your commitment and dedication, the relationships that come out of it are like the roots of a tree — deep and wide.”
Simon Grunberger, President of Grunberger Diamonds Japan
The company is also preparing its next phase of growth. Grunberger said it plans to establish Grunberger Diamonds India before the end of the year to expand manufacturing know-how and offer a wider range of goods worldwide, from tiny melee diamonds to larger sizes, and from round brilliants to fantasy shapes.
He also said the group became Responsible Jewellry Council compliant at the end of 2025 and already provides customers full traceability and transparency on the goods it offers.
Now in its fourth generation, with family members active across operations, Grunberger Diamonds continues to blend Antwerp craftsmanship with international reach, supplying natural, precisely calibrated melee diamonds that support designers and manufacturers across Europe, the United States, Japan and beyond.
