"Rosso Entratico” belongs, from an aesthetic point of view, to the commercial category of “red marbles” and in particular to a variety of sedimentary rock (limestone). In this type of rock, the red colour is always associated with the presence of haematic micro-dispersions.

...“Rosso Entratico” is an historic stone material boasting ancient quarrying traditions around Bergamo, famous for several varieties of historic and/or contemporary stone materials (Vola & Primavori, 2009, with bibliography). It saw traded in the 1900s under the name “Rosso del Cherio”. The colour and pattern of undeteriorated material are very similar to that of the more famous “Rosso Verona” althought the colour is darker. The quarries of origin, today both abandoned, are located in the lower Val Cavallina, about 20 km east of Bergamo, in the Entratico and Selva di Zandobbio area. Mention in the literature in the first half of the 1800s (Maironi da Ponte, 1819), its use is proven in the “Andrea Galletti” decorative stone collection donated to the Bergamo Museum of Natural History in 1887 (Paganoni & Carmelenghi, 1987).

...Use in local rustic buildings is without doubt very ancient: testimony includes the ashlars of historic walls in Entratico and localities around quarrying areas. The most ancient known application, for ornamental purposes, is the gate of the Rotonda di San Tomè at Almenno San Bartolomeo (Valle Brembana), an ecclesiastic building with a circular ground plan in the Bergamo Romanesque style, dating from the first half of the XII century (Bugini & Folli, 2008). Rota Nodari & Manzoni (1997) suggest that the material used in this building would belong, on the other hand, to the Calcare Selcifero Lombardo formation .

"Rosso Entratico” was later used to produce capitals, jambs, ledges, columns and wall cladding, often with inlays, in the most important buildings of Città Alta (high town) of Bergamo. In short, it is to be found in the monolithic columns of the access staircase to Palazzo Vecchio, the rhombus cladding of the facade of the Colleoni Chapel (the work symbolising the Lombard Renaissance completed in 1476 by Giovanni Antonio Amedeo), the 1400s gate to the home of Bartolomeo Colleoni, the wall cladding and inlay friezes of the terrace of Palazzo Terzi and lastly in the floorings and gates of the Baronial Hall in Malpaga castle at Cavarnago (Rodolico, 1953; Paganoni, 1987; Bugini & Folli, 2008).

"Rosso Entratico” was sometimes confused with the more famous “Rosso Verona” (see, for example, Angelini & Longaretti, 1964). Just like the material from the Veneto, the calcitic composition, nodular texture and clay component are responsible for various forms of deterioration, such as flaking, loss of cohesion, gaps, black crusts and loss of colour.

In the outcrop area, this marble was quarried for dry stone walls ashlars probably since the first prehistoric settlements in the lower Val Cavallina. Quarrying activity is documented after the Second World War, achieving maximum expansion in the 1960s-70s (Anon., 1966; 1975).
As well as the two historic quarries - Via Corna Rossa in Selva di Zandobbio and in Via Valle della Vena south of Entratico itself - quarrying activity in the past probably also involved other outcrops belonging to the same stratigraphic interval in the Southalpine Foothills between Brianza and Lago d’Iseo (Bersezio et al., 1990).

Trade varieties, sold from the second post-war period until the 1960s, included the following: “Rosso del Cherio Macchiato”, "Rosso del Cherio Perlato” and “Rosso del Cherio Venato” (Pieri, 1964; Bigioggero et al., 2000). Other commercial names were used in the recent past, such as “Rosso Radica” and "Rosso Orobico” (Blanco 1991). The latter name, in particular, created evident confusion, given the contemporary availability on the market of the similarly-named yet much more famous “Marmo Arabescato Orobico Rosso” quarried in the middle Valle Brembana and belonging to a different stratigraphic boundary.