Like slate, phyllite is a ‘foliated metamorphic rock created from fine-grained sediments’ but, dating back more than 545 million years, it’s many millions of years older and could be considered as being ‘super-slate’ or ‘slate plus’ – slate that’s been subjected to a longer period of metamorphic ‘processing’ and has benefited accordingly.
Phyllite shares slate’s essential characteristics but surpasses its qualities – it is generally stronger and more resilient than slate – making it an outstanding natural building material for use as either roofing slates or architectural stone. (Note the distinction between slate, the rock, and roofing slates.) Phyllite has a slightly different mineral composition to slate; its main constituents of quartz, muscovite and chlorite result in an attractive medium-grey rock with a slight green tinge and a subtle metallic sheen. It can also contain brilliant veins of quartz that can add lightning-streak drama to its appearance.
Riverstone® architectural stone is available in either a comprehensive range of floor and wall tiles, cladding, stair treads and risers, sills and skirtings, decorative panels and worktops or, to offer designers total creativity and flexibility, on a bespoke, cut-to-size basis. Four different surface finishes are available that accentuate the rock’s natural characteristics: these range from a natural riven finish that provides floor tiles and stair treads with high levels of slip resistance to a honed, silk-smooth surface for wall tiles and worktops.
Phyllite’s properties have made it a prized building material and one that’s been used for thousands of years in the region in which it’s quarried and, not surprisingly, it’s been equally well received since ‘going international’: Riverstone® architectural stone has been used to clad the walls of the Grand Buffet in Macau’s opulent Grand Lisboa Hotel and Casino; in the reception area and bar of the new Hilton Helsinki-Vantaa Airport hotel; as flooring in the next seven branches of the Kreissparkasse Weidenbrück bank being built throughout northern Germany and in the foyer of the Prestonpans Library near Edinburgh.