DIATHEKE, the swiss specialist now part of Rosy Blue

Established in 1960 as a diamond trader, the Antwerpbased Rosy Blue group reported revenue of $1.1 billion in 2024. Employing more than 3,600 people across four continents, it operates five manufactures in India and Botswana. Still family-owned—with CEO Ravi Bhansali representing the third generation—, the group now plans to extend its services to the luxury industry, particularly in Europe. Key to this strategy is DIATHEKE, led by Théo Massaoutis and highly regarded by this demanding clientele for its agility and the quality of its expertise. Rosy Blue, which already supplies diamonds to most jewelers on Place Vendôme, intends to go further by developing a manufacture that brings together the full range of watch- and jewelry-making services—design engineering, CNC machining, gem-setting, jewelry, and polishing—under one roof. This is complemented by expertise in colored stones, supported by the recent opening of a cutting manufacture in Bangkok by Rosy Blue Thailand. Such a breadth of capabilities in a single location is rare in the profession. For the customer, it means greater efficiency and enhanced quality. Teams work in synergy, planning and adapting tasks to ensure a seamless workflow between departments and continuous quality improvement. “From series production to one-off pieces, from watches to high jewelry, we bring every stage—from development to manufacturing—into a single structure,” says Théo Massaoutis. “Customers can provide us with an image, a sketch or an idea, and we’ll manufacture the project from A to Z to deliver the finished piece.” Help customers achieve their vision Reliability and expertise are fundamental for any business operating in the luxury sector, and Ravi Bhansali offers both: the assurance of a trusted diamond manufacturer combined with the know-how of a specialist Swiss workshop. As he explains, “we aim to support our customers' needs, help them achieve their vision and respond quickly and precisely to resolve their technical challenges.” Bringing every stage together within a single structure is also consistent with the group’s longstanding commitment to traceability. As one of the founders of the Responsible Jewellery Council - which defines and certifies ethical and responsible practices for the industry - Rosy Blue has a strong role to play. Customers’ growing ESG expectations are driving increased investment in blockchain-based initiatives, certification and R&D… something Ravi Bhansali and Théo Massaoutis see not as an obligation, but a mission. The success of this alliance between the two entities will come from their ability to combine their expertise while preserving their DNA of family values, ethics, quality and agility. The greatest challenge will no doubt be to reconcile quality with agility, and to sustain excellence as they grow within a market where reputations are forged over decades.