The Ostro Topaz: A Gemmological Legacy at the London Natural History Museum

For the collector and the connoisseur, the journey of a gemstone, from its raw state deep within the earth to its final, polished form, is a profound narrative. At Melanie Katsalidis, our appreciation for this journey is why we are drawn to the story of the Ostro Topaz: a monumental stone that perfectly encapsulates the marriage of geological marvel and human design.

The 'Ostro Stone,' a flawless, faceted blue topaz weighing an impressive 9,381 carats (almost two kilogrammes), is the largest of its kind on permanent loan to the London Natural History Museum. More than just a record-breaker, it represents a pivotal moment in the history of blue topaz, the very material we champion in Melanie's signature designs.

The Max Ostro Legacy

The man behind this incredible stone and its subsequent market impact was British explorer Max Ostro. Beginning his quest for exquisite gems in the 1960s, his journey took him to the most remote corners of the globe. His prize, the original rough material for the Ostro Stone, was discovered three decades ago deep in Minas Gerais, Brazil.

Max Ostro’s real legacy, however, is deeply connected to the blue Topaz that forms the core of many contemporary collections. Ostro Minerals, the company he founded, was responsible for naming the now-industry-standard colours of blue topaz: Sky Blue, Swiss Blue, and the deep, sophisticated tone we favour at Melanie Katsalidis, the London Blue. This singular company defined the luxury market for the stone, setting the chromatic standard for designers worldwide.

The final Ostro Stone, an impressive faceted gem 15 centimetres long, is a stunning example of how skilled craftsmanship elevates a natural specimen. As Mike Rumsey, Senior Curator of the Minerals Collection at the Museum, noted:

"This stone is an excellent example of how humans have crafted beautiful and desirable objects from the natural mineral specimens we find around us... it is a stone crafted with a great sense of form and proportion."

This perspective resonates deeply with Melanie's own design philosophy. The Ostro Stone is a macro-example of the structural integrity, clarity, and precision we demand in the micro-scale of our fine jewellery. Like our own London Blue Topaz pieces, the stone's vivid colour is the result of careful, controlled treatments on the uncut material, which enhances the pale blue colour naturally found in the Topaz deposits.

What We Love About Topaz

We select Topaz for its structural strength (Mohs 8) and its ability to hold a clean, architectural form. Melanie will also have topaz custom cut for her designs, like the hexagonal cuts you see in her collections, were all cut to her specifications in Brazil. It's also a relatively affordable gemstone, pricing lower than the highly prized sapphire, but demonstrating excellent colour and clarity. 

Ready to wear a piece of geological history defined by its structure and colour?

👉 Discover our current collection of London Blue Topaz and other coloured gemstone designs by Melanie Katsalidis online, or inquire about a bespoke piece.