Bagnada-Ponticelli Mine (ex-Bolognini Mine; ex-Unitalc Mine), Lanzada, Sondrio Province, Lombardy, Italyi

Regional Level Types
Bagnada-Ponticelli Mine (ex-Bolognini Mine; ex-Unitalc Mine)	Mine
Lanzada	Municipality
Sondrio Province	Province
Lombardy	Region
Italy	- not defined -

Talc mine located to the north-west of Tornadri, at an elevation of about 1180 m, on the left bank of Lanterna stream.
The mine has been re-activated for touristic and cultural purposes
(see external link).

Provided coordinates are still approximate but at least refer to the buildings of "Museo della Bagnada".

The mine exploits the Brusada-Largone talc (steatite) body, consisting of two main EW-oriented veins varying in thickness from 5 to 10 m. These veins are composed of a carbonate-rich contact zone towards the embedding serpentinite and a central talc schist zone with dolomite nodules. The carbonate-rich zone mainly consists of talc and magnesite with some accessories (antigorite, clinochlore, dolomite, and magnetite). Talc is the main component of talc schist in association with magnesite, clinochlore, and opaque accessories (heazlewoodite, pyrrhotite, and violarite) (Bedognè et al., 1993; Bedognè, 2006). Minor accessories of the Brusada-Largone talc body include Ni-bearing pyrite, chalcopyrite, Cr-bearing spinel, rutile, ilmenite, Co-bearing pentlandite, millerite, siegenite, and vaesite. Furthermore, awaruite is present in talc-bearing serpentinite (Gorga, 1991 and 1993a; Bedognè et al., 2006).

Interesting minerals are contained in the waste rocks originated from mining operations: magnesite and dolomite crystals in clefts inside talc-bearing serpentinite; titanian hydroxylclinohumite, forsterite, magnetite, and apatite in calcite veins inside serpentinite; Ti-Ni-Cu minerals and other species (native copper, millerite, pyrite, brookite, ilmenite, magnetite, dolomite, calcite, magnesite, gypsum, hydroxylapatite, xonotlite, palygorskite, and saponite) in carbonate veins (hydrothermalites) inside serpentinite; anatase in fissures inside calc-schists (Bedognè et al., 1993; Bedognè, 2006; Bedognè et al., 2006). Furthermore, a chromitite lens in serpentinite, intersected by the excavation works, has yielded chromite, chromian clinochlore, perovskite, and calcite. From fissures in chromitite bright emerald-green crystals of chromian andradite have been recovered (Bedognè et al., 1993; Sciesa, 1993).

Note on “Ti-bearing clinohumite, titanclinohumite”:
according to the analyses performed, this mineral in the Malenco valley serpentinite is practically fluorine-free (Trommsdorff and Evans, 1980). Therefore, after the institution of the new species hydroxylclinohumite in 1999, all records of “titanclinohumite” in the antecedent literature and specimens preserved in public and private collections consequently labelled are now Ti-bearing hydroxylclinohumite (Bedognè et al., 2006).

Other Regions, Features and Areas containing this locality

References