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Trinity research on Valentia Slate results in its designation as a Heritage Stone

Valentia Slate, a natural stone which has been used since at least 1816, has recently been awarded the Status of “International Union of Geological Sciences Heritage Stone”. This coveted status is awarded only to stones that have a long history of significant use and which are still available for conservation purposes. Valentia Slate has been used in many landmark buildings internationally, including the floors and roofs of the House of Commons in London, and in 2022 was used to reroof the Rubrics in Trinity. Valentia Slate joins Connemara Marble as the only Irish stone types currently with this designation of which there are 55 globally.

Research by the Trinity research group STONEBUILT Ireland ( based in Geology in the School of Natural Sciences and led by Professor Patrick Wyse Jackson and Dr Louise Caulfield, in collaboration with colleagues at Valentia Slate Company Ltd and Carrig Conservation Consultants, has resulted in this global designation.

Valentia Slate has all of the qualities needed for excellence in construction and domestic use. It is extracted underground on Valentia Island in the same facility that was opened by Peter Fitzgerald, the Knight of Kerry, in 1816. The company operates a zero-waste policy in extracting slate for a wide variety of purposes including flooring, roofing slates, kitchen countertops and funerary headstones.

Worldwide, buildings are major emitters of greenhouse gases. Natural stone is a very low-carbon building material and Valentia Slate is delighted to be part of a modern trend to use more natural stone and timber in architecture, simply because this approach is better for the climate.

Professor Patrick Wyse Jackson noted that “Valentia Slate is a unique stone type that only occurs in Co. Kerry. Its characteristics allowed it to be split into roofing slates but also large slabs and it was utilised for a wide variety of domestic and commercial applications. Amongst the more unusual uses were for headstones, garden benches, billiard tables, water tanks, and walling for bonded warehouses. The research project STONEBUILT Ireland, funded by the Geological Survey Ireland and Office of Public Works, enabled research on this important sustainable commodity.”

Aidan Forde, a geologist, is owner of Valentia Slate Company Ltd and commented: “This recognition is also of the expert and hard-working staff of Valentia Slate who have made the company what it is today. This award is recognition, not only of their own efforts in keeping Valentia Slate available for use in sustainable construction, but also the work of the many generations of South Kerry people who worked at the quarry.”

Peter Cox, a material scientist, is founder and managing director of Carrig Conservation International Limited and has forty years of experience in the Conservation of historic Buildings across the world. He commented: “Valentia Slate is one of the purest and finest products I have come across in my forty years working in this sector. The material has been used on many very important international buildings; it is vitally important that historic materials such as Valentia Slate are available for conservation and repair of these buildings. It is an added bonus that slate is now available from an Irish source to reduce carbon in our modern construction market”.

For further information or further imagery please contact Aidan Forde at +35386.2398008 or Aidan Forde

The free access scientific article published in the Irish Journal of Earth Sciences on which the Heritage Stone status is based is available here

For further information on the International Union of Geological Sciences Heritage Stone programme please contact Patrick Wyse Jackson


Split slab of Valentia Slate

Split slab of Valentia Slate

Headstones of Valentia Slate at Caherciveen Old Church, Co. Kerry

Headstones of Valentia Slate at Caherciveen Old Church, Co. Kerry