Vert de Salvan

Geologically it is a Permian coarse clastic sedimentary rock — a conglomerate or breccia from the Permian period (around 280 to 250 million years ago) formed in a former continental alluvial fan or river delta environment. During that time, rounded to subangular rock clasts of differing origin were deposited in a fine-grained matrix and subsequently cemented into a solid rock by carbonate and quartzitic cementation. The characteristic greenish tonality results from chlorite- and epidote-bearing mineral components in the groundmass, which are typical of the Alpine metamorphic influence on Permian sediments. Important: in the stone trade the stone is occasionally misclassified as a “gneiss” — the DNSA classification as a coarse clastic rock is petrographically correct, since the rock has retained its original conglomerate structure despite the Alpine metamorphic influence.

Visually, Vert de Salvan is characterised by an exceptionally characterful, almost museum-like material signature. Over a greenish-grey to olive-green fine-grained groundmass, rounded to subangular rock clasts of differing size and colouring spread out — from a few millimetres to several centimetres in diameter, in tones from light cream-white through mid green to dark green and occasionally silvery and micaceous. The individual clasts appear like petrified pebbles in a mineral matrix — a slab image that looks like a petrified Alpine stream bed. The slab-to-slab variation is considerable and is an essential characteristic of the stone. The material signature differs clearly from typical marbles or granites and creates a distinctive Alpine identity that has been valued in the Swiss building tradition for centuries.

Technically Vert de Salvan ranks among the highest-quality Alpine dimension stones, with documented DNSA values: bulk density 2735 kg/m³, compressive strength 88 MPa, flexural strength 28.9 to 31.1 MPa (exceptionally high and typical of granite), water absorption of only 0.17 % (extremely low), abrasion resistance 6.8 cm³/50 cm² (moderate — typical of a conglomerate). The low water absorption and the high flexural strength qualify the stone for demanding interior and constructively protected external applications. Its frost resistance is DNSA-documented. An important technical particularity: DNSA notes a partial acid sensitivity — individual mineral constituents are not permanently acid-resistant, which should be taken into account in care. In addition, only a matt gloss is achievable — no mirror-like high polish — a material-specific property owed to the natural character of a conglomerate and one that corresponds perfectly to the Alpine, rustic appearance of the stone.

In interior fit-out, Vert de Salvan is an exceptional choice for classically Alpine, rustically elegant and Swiss historically inspired architecture. Classic applications are wall claddings, fireplace surrounds — a traditional Swiss application of the stone — façade claddings, floor surfaces of moderate frequency, stair treads and plinth formations. The greenish-grey tonality with its characteristic pebble clasts harmonises particularly with warm timber fittings in the Alpine tradition (larch, spruce, oak, chestnut), with brass, bronze and copper accents and with muted earth tones. Vert de Salvan is a stone for architecture that seeks cultural-historical depth and a distinctively Alpine Swiss character. Outdoors it finds use for façade claddings and plinth formations — its frost resistance and low water absorption qualify it for Central European climatic conditions, though its moderate abrasion resistance limits use on intensively used external surfaces.