The Osmium Institute is the global authority on osmium—the rarest and most valuable precious metal in the world. Dedicated to the scientific authentication, documentation, and ethical trade of crystalline osmium, the Institute serves as the central certifying body for jewelers, investors, and collectors worldwide. Through education, research, and industry partnerships, the Osmium Institute ensures transparency and trust in the osmium market while promoting the metal’s unique beauty and structural integrity. With offices and certified partners in over 30 countries, the Institute is at the forefront of introducing this extraordinary element into the worlds of fine jewelry, watchmaking, and strategic investment.

The world doesn't need more jewelry. Why become a jeweler?

Andrew Slesinger is a sixth-generation diamond dealer and the owner of Rough Diamond World, a New York-based wholesale company specializing in natural rough diamonds. Raised in the traditions of the diamond trade, Andrew’s path was shaped from a young age by the values of trust, precision, and quiet excellence passed down through his family.Operating out of Manhattan’s famed Diamond District, Andrew has built a reputation as a discerning eye in the world of rough—sourcing, evaluating, and moving diamonds through tightly held industry relationships. He represents a lineage of old-school expertise while navigating the pressures of a rapidly modernizing market. Known for his candor, integrity, and deep respect for the craft, Andrew remains committed to keeping the heritage of diamond dealing alive—one handshake, one stone, and one honest deal at a time.