Arzo marble (Canton Ticino, Switzerland) is a breccia that is mainly reddish in colour but in some cases can also tend towards yellow and grey.
It should be noted that, from a petrographic point of view, it is not a true marble.
It can be divided into three main varieties, each with different shapes: Brocatello d’Arzo, Macchiavecchia (red, yellow or grey) and Rosso d’Arzo.
This breccia is only partially resistant to atmospheric agents and almost completely non-resistant to frost. Being a limestone, it is also sensitive to acids.
In this case, Macchiavecchia is a limestone breccia with angular and sharp rock fragments ranging from a few millimetres to several decimetres. The colour range of these fragments varies from predominantly grey-brown to dark grey, yellowish and pale purple to greenish. The base mass in which the fragments are found is reddish-brown, flesh-red or yellow in colour. Finally, a white vein can be seen running through the rock.
References for use of material
Redevelopment of the Arzo Quarries, architect Enrico Sassi, Arzo (Switzerland).
The main source of the description
Material-Archiv. (2024). Arzo-Marmor.
The original source of the characteristic values
Kündig, R. et al. (1997). Die mineralischen Rohstoffe der Schweiz. Zurich: Schweizerische Geotechnische Kommission, p. 253.
