Quarried exclusively in a small basin of the Cottian Alps in Piedmont, Luserna Stone is an icon of Italian architecture and urban planning. Famous for its silver reflections and its indestructibility, it is the skin that covers historical roofs and Savoy squares.
Luserna Stone is an orthogneiss, a metamorphic rock derived from the profound transformation of ancient granitic rocks under immense tectonic pressures and temperatures. This process stretched and aligned the constituent minerals (quartz, feldspar, and micas) in parallel bands. This layered arrangement, called schistosity, is the most important engineering characteristic of the material: it allows quarriers to insert wedges and "split" the block along perfect planes, obtaining very thin but exceptionally strong slabs, impossible to obtain from ordinary granite.
In addition to its formidable compressive strength, the almost total absence of porosity (< 0.3%) makes Luserna Stone totally unassailable by frost and de-icing salts spread on winter roads. Aesthetically it stands out for the high concentration of phengite (a mica) which gives the split surface a metallic brilliance. It exists in three natural chromatic variants: "Blue-Grey" (the most classic), "Mixed" (with warm golden/brown veins due to iron oxidation), and the rare "Green".
Standards
European and international references applicable.
Physical properties
Usage environment
Luserna Stone is totally unassailable by frost and de-icing salts spread on winter roads. Aesthetically it is distinguished by the high concentration of phengite (a mica) which gives the split surface a metallic brilliance.