László and Elsa Horváth are prominent figures in the Canadian mineralogical community, best known for their extensive work documenting the mineralogy of Mont Saint-Hilaire (MSH) in Quebec. Their contributions have bridged the gap between amateur collecting and professional mineralogical research. I was introduced to them by fellow Canadian, Ray Hill, at the 2014 Tucson Show.
While they have collected globally, their legacy is inextricably linked to the Poudrette quarry at Mont Saint-Hilaire. They spent decades systematically collecting, cataloging, and photographing specimens from this alkaline complex, which is one of the most mineralogically diverse sites in the world.
The Horváths are noted for their collaboration with professional mineralogists and institutions like the Canadian Museum of Nature. They have been instrumental in the discovery of several new mineral species by providing well-characterised specimens for analysis.
They have authored and co-authored numerous articles in journals such as The Mineralogical Record and Rocks & Minerals. Their most significant written contribution is often cited as the definitive topographical mineralogy of Mont Saint-Hilaire, which serves as a vital resource for both researchers and collectors.
Their work was formally recognised by the International Mineralogical Association (IMA) through the naming of horvathite-(Y), formula NaY(CO3)F2. It was discovered at the Poudrette quarry, Mont Saint-Hilaire and typically appears as very small, colourless to pale yellow or beige crystals, often in fibrous or platy aggregates. It is a rare rare-earth carbonate mineral found in hydrothermal cavities within sodalite syenite.
The Horváths are often cited as a prime example of “citizen scientists.” Their meticulous approach to labelling and site-specific history has ensured that their collection—parts of which have been acquired by major museums—retains its full scientific value. For collectors interested in alkaline massifs or rare-earth element (REE) minerals, their documentation is considered the gold standard for Canadian mineralogy.
The horvathite-(Y) specimen below came from the Horváths via Jocelyn Thornton, a well-known New Zealand micromounter. In recent times, Jocelyn has been distributing much of her collection to others, and I was fortunate to be the recipient of her Mont Saint Hilaire micros.
Below: László and Elsa Horváth at the 2014 Tucson Show.
Below: Horváthite-(Y), Analcime, Albite, Rhodochrosite, Poudrette quarry, Mont Saint-Hilaire, Québec, Canada. Width of view 5mm.
