Abstract Villamayor Stone (VS) is an arkosic stone and is known by several names: (i) VS because the quarries are located in Villamayor de Armuña village (Salamanca, Spain); (ii) Golden Stone due to its patina, which gives the stone a ochreous/golden colour; (iii) Franca Stone is known locally and in historical documents. VS has several varieties ranging from channel to floodplain facies. In this work, we have selected three varieties. VS was quarried and used in the construction of Romanesque monuments such as the Old Cathedral, Gothic monuments including the New Cathedral and the University façade, and Baroque monuments, notably the Main Square. Also, VS was used in the reconstruction of the Roman Bridge (Salamanca, Spain). Currently, VS is quarried by a small number of family businesses, using traditional methods for cladding façades of new buildings. Unfortunately, part of the construction sector went bankrupt in the 2008 crisis. However, VS is still the main stone used in the city of Salamanca for the restoration of monuments, even though used in relatively small quantities in comparison with usage before the economic crisis. It is thus of great importance for future generations that their quarries and the craft of masonry be protected. This work proposes that VS should be designated as a Global Heritage Stone Resource.

Abstract Échaillon stone, a Mesozoic platform limestone from SE France, is proposed as a Global Heritage Stone Resource. The Échaillon stone quarries are located at the western termination of the Alps, near the city of Grenoble. Stone from the main Échaillon quarries is an Upper Jurassic to Berriasian bioclastic near-reef limestone, renowned for its two characteristic white and pink colours. Two ancillary quarries nearby, the Lignet and Rovon quarries, provided the Lower Cretaceous (Barremian to Aptian) Yellow Échaillon stone, of lagoonal origin. Échaillon stone's unique characteristics, resistance to weathering and high aesthetic values made it a prized building and ornamental material used in many significant historical buildings in Europe, North Africa and the USA. Although the first use of Échaillon stone in buildings dates from the Gallo-Roman period, the industrial use ranges from the mid-nineteenth century, during the heyday of the Beaux-Arts architecture period in France, to the mid-twentieth century. The reputation of Échaillon stone was bolstered by world-renowned architects, sculptors and artists who used it for historical building ornament and sculptures. By the turn of the twentieth century, production started to decline and it ceased by the middle of that century.

Abstract Connemara Marble, a well-known distinctive decorative stone from the west of Ireland, is herein proposed as a Global Heritage Stone Resource. Connemara Marble is a sillimanite-grade ophicarbonate, dominated by dolomite and calcite with varying proportions of serpentine, diopside, forsterite, tremolite clinochlore and phlogopite. The marble displays intricate corrugated layers that range in colour from white through sepias to various shades of green. These features impart unique characteristics that set the marble apart from other ornamental stones. Characteristics reflect amphibolite-grade metamorphism of an impure siliceous dolomitic limestone during the Grampian orogeny (475–463 Ma). Olivine, diopside, tremolite along with calcite and dolomite were formed during the peak of metamorphism which was followed by a later pervasive hydrothermal metamorphism that led to the extensive growth of serpentine after olivine and diopside. It has been used since Neolithic times, but has been quarried and fashioned in Connemara since the eighteenth century, and widely utilized in buildings in Ireland and the UK, for cladding, banisters, columns and church fittings. Later in the late nineteenth and early twentieth centuries it was exported in large quantities to the USA for use in civic and educational buildings. Its many uses as an ornamental stone in the interiors of buildings and in Irish jewellery commands worldwide acclaim.

Abstract The proposal to designate those natural stones that have achieved widespread utilization in human culture was first mooted in late 2007, and first presented in a public forum at the 33rd International Geological Congress in July 2008. Over the next four years, a network of international correspondents was created, circulars were distributed, a website was established and formal rules were adopted, all with the focus of establishing the ‘Global Heritage Stone Resource’ designation. During the 34th International Geological Congress in July 2012, the Heritage Stone Task Group was formally established under the auspices of the International Union of Geological Sciences, in association with the International Association of Engineering Geology and the Environment, Commission C-10 Building Stones and Ornamental Rocks, and with a formal Board of Management. It has now been recognized that the new designation has value both in offering a mechanism to promote the safeguarding of stone resources, as well as in the formal definition of stone types within sufficiently tight parameters that it can facilitate name protection. For the future, the Board of Management needs to encourage and approve nominations for the new designation. As well, an annual conference needs to be organized.

Abstract Piedra Pajarilla is the local name under which the Martinamor granite was known when it was quarried during the 19th century. It is a leucogranite of Hercynian age, and here we present its formal nomination as a ‘Global Heritage Stone Resource’. Piedra Pajarilla fits the proposed designation because it has been used for centuries in the construction of major historical and famous buildings in Salamanca, leading the city to being included in the UNESCO World Heritage list in 1988. Piedra Pajarilla is no longer quarried, and this nomination will help to maintain the historical quarry for the restoration of the monuments if blocks need to be replaced.

Abstract Colmenar Limestone is one of the traditional materials most commonly used in monuments in Madrid, Spain. The petrophysical properties of this stone determine its high resistance to decay. Its low water absorption and pore size distribution favour good hydraulic behaviour, which is likewise furthered by its high ultrasound velocity and low anisotropy. The durability findings pursuant to the 280 freeze–thaw, 42 thermal shock, 30 salt crystallization and 120 salt mist cycles conducted confirmed the stone’s resistance to decay in these simulated aggressive environments. The mass loss recorded in the samples and the variation in petrophysical parameters were generally very low after all except the salt crystallization trials, which induced loss of cohesion on the stone surface, increased roughness and the formation of concentric microcracks, sub-parallel to the more exposed surface, that also affected the arris and vertices of the specimens tested.