Description
Dark grey uniform sandstone with medium to fine grain and orientation parallel to the layer of constituent granules.
Rock without cavities or micro cracks, the interstices are completely occupied by the fine crystalline component and abundant carbonatic concrete. It is formed by fragments of carbonatic rocks, micro fossil shells, fragments of silicate rock, quartz, feldspars and rare mica.
According to the petrographical study and Zuffa NCE-CE-CI diagram (1980), Colombino is classified as calcarenite.
In terms of its physical and mechanical characteristics, it can be defined as a stone that is compact, easy-to-work, with very little porosity and frost-resistant. It possesses excellent mechanical resistance and resistance to wear and tear, even in particularly unfavourable conditions.
Petrographic definition: sandstone
Mass of Unit Volume: 2690 Kg/m3
Water absorption: 0.27%
Compression breaking load simple: 192 MPa
Breaking load simple compression after freezing: 113 MPa
Relative Abrasion coefficient (referring to s. Fedelino granite): 0.60
Impact resistance: minimum fall height: 15 cm
Even inconsistency index of hardness:
Source: Centro Ceramico Bologna