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Sferlùn asbestos mine, Vallone del Cengiaccio (Cengiaccio; Cengiàsc; Cengiasco), Lanzada, Lanterna Valley, Malenco Valley, Valtellina, Sondrio Province, Lombardy, Italyi
Regional Level Types
Sferlùn asbestos mineMine
Vallone del Cengiaccio (Cengiaccio; Cengiàsc; Cengiasco)- not defined -
LanzadaMunicipality
Lanterna ValleyValley
Malenco ValleyValley
Valtellina- not defined -
Sondrio ProvinceProvince
LombardyRegion
ItalyCountry

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Key
Latitude & Longitude (WGS84):
46° 16' 9'' North , 9° 54' 9'' East
Latitude & Longitude (decimal):
Locality type:
Köppen climate type:
Nearest Settlements:
PlacePopulationDistance
Lanzada1,365 (2014)2.6km
Caspoggio1,375 (2014)3.2km
Vassalini247 (2014)3.3km
Santa Elisabetta123 (2014)3.4km
Chiesa in Valmalenco2,203 (2014)4.1km
Name(s) in local language(s):
Miniera di amianto dello Sferlùn, Vallone del Cengiaccio (Cengiaccio; Cengiàsc; Cengiasco), Lanzada, Lanterna Valley, Valmalenco (Val Malenco), Valtellina, Sondrio, Lombardia


Old asbestos mine, located in abrupt and diffcultly accessible place on the southern slope of Palla del Cengiaccio, at an elevation of about 1875 m, on the right side of Vallone del Cengiaccio (Cengiàsc in the local dialect).
The access to this dangerous place is possible only following the path that originates from the road Franscia-Campo Moro (1780 m), crosses the bridge on Largone stream, passes through Alpe Largone inferiore and goes to Bocchetta del Cengiaccio (1923 m), from where it leads down to the old asbestos mines of the steep Vallone del Cengiaccio, looking down on Lanterna valley. The underground mine is opened in the upper part of a rocky wall and can be reached by walking along a narrow ledge.
This mine has yielded the best demantoid specimens of all Malenco valley: in particular, outstanding specimens were collected in 1947 and in the period 1966-1972.
Demantoid crystals from Sferlùn tipically show rhombododecahedral habit and sometimes reach the notable size of 20-30 mm; in large crystals the colour usually varies from olive-green to yellow-greenish, emerald-green colour is sometimes observed in small crystals. Crystals are usually disseminated in asbestos or perched on the walls of the serpentinite fissures, but, sometimes, they form grass-green nodular aggregates (up to 2 kg !), which the miners named “asbestos seed” (“semenza d’amianto”) or “acorns” (“ghiande”). Asbestos (chrysotile) appears in white or pinkish fibres (up to 2 m !! in length). Accessory minerals include magnetite, carbonates and lamellar brucite.
Furtermore, magnetite, native copper and alteration minerals are known from carbonate veins (hydrothermalites) in serpentinite.

Nowadays, there is almost nothing, given the frequent visits and the findings in the years 1980 - 2000.

Note: the name Sferlùn, given to this mine, in the local dialect means deep split in the rock and it can be considered the augmentative of the Lombard word “sferla”, that signifies gash, tear.
The name Cengiàsc (Italianised in Cengiaccio or less commonly in Cengiasco) is the augmentative of the word “cengia”, that means ledge, shelf.

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.


Mineral List


13 valid minerals.

Detailed Mineral List:

Andradite
Formula: Ca3Fe3+2(SiO4)3
Reference: Bedognè, F., Montrasio, A., Sciesa, E. (1993) I minerali della provincia di Sondrio: Valmalenco. Bettini, Sondrio, 275 pp. Van King; Giovanni Scapin specimen
Andradite var: Demantoid
Formula: Ca3Fe3+2(SiO4)3
Reference: De Michele, V. (1974). Guida mineralogica d'Italia. Istituto Geografico De Agostini, Novara, 2 vol. ; Giovanni Scapin specimen
Antigorite
Formula: Mg3(Si2O5)(OH)4
Reference: Bedognè, F., Montrasio, A., Sciesa, E. (1993) I minerali della provincia di Sondrio: Valmalenco. Bettini, Sondrio, 275 pp.
Aragonite
Formula: CaCO3
Reference: Gramaccioli, C.M. (1975): Minerali alpini e prealpini. Istituto Italiano Edizioni Atlas, Bergamo, 2 vol., 472 pp.
Brucite
Formula: Mg(OH)2
Reference: Bedognè, F., Montrasio, A., Sciesa, E. (1993): I minerali della provincia di Sondrio: Valmalenco. Bettini, Sondrio, 275 pp.
Calcite
Formula: CaCO3
Reference: Bedognè, F., Montrasio, A., Sciesa, E. (1993): I minerali della provincia di Sondrio: Valmalenco. Bettini, Sondrio, 275 pp.
'Chlorite Group'
Reference: Bedognè, F., Montrasio, A., Sciesa, E. (1993) I minerali della provincia di Sondrio: Valmalenco. Bettini, Sondrio, 275 pp.
Chrysotile
Formula: Mg3(Si2O5)(OH)4
Reference: De Michele, V. (1974). Guida mineralogica d'Italia. Istituto Geografico De Agostini, Novara, 2 vol.
'Clinochrysotile'
Reference: Van King
Copper
Formula: Cu
Reference: Bedognè, F., Montrasio, A., Sciesa, E. (1993): I minerali della provincia di Sondrio: Valmalenco. Bettini, Sondrio, 275 pp.
Diopside
Formula: CaMgSi2O6
Reference: Bedognè, F., Montrasio, A., Sciesa, E. (1993) I minerali della provincia di Sondrio: Valmalenco. Bettini, Sondrio, 275 pp.
Forsterite
Formula: Mg2SiO4
Reference: Bedognè, F., Montrasio, A., Sciesa, E. (1993) I minerali della provincia di Sondrio: Valmalenco. Bettini, Sondrio, 275 pp.
Hydroxylclinohumite
Formula: Mg9(SiO4)4(OH)2
Reference: Simone Boscolo
Lizardite
Formula: Mg3(Si2O5)(OH)4
Reference: Van King
Magnetite
Formula: Fe2+Fe3+2O4
Reference: Bedognè, F., Montrasio, A., Sciesa, E. (1993): I minerali della provincia di Sondrio: Valmalenco. Bettini, Sondrio, 275 pp.
Pyroaurite
Formula: Mg6Fe3+2(OH)16[CO3] · 4H2O
Reference: Bedognè, F., Montrasio, A., Sciesa, E. (1993) I minerali della provincia di Sondrio: Valmalenco. Bettini, Sondrio, 275 pp.

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
Copper1.AA.05Cu
Group 4 - Oxides and Hydroxides
Brucite4.FE.05Mg(OH)2
Magnetite4.BB.05Fe2+Fe3+2O4
Group 5 - Nitrates and Carbonates
Aragonite5.AB.15CaCO3
Calcite5.AB.05CaCO3
Pyroaurite5.DA.50Mg6Fe3+2(OH)16[CO3] · 4H2O
Group 9 - Silicates
Andradite9.AD.25Ca3Fe3+2(SiO4)3
var: Demantoid9.AD.25Ca3Fe3+2(SiO4)3
Antigorite9.ED.15Mg3(Si2O5)(OH)4
Chrysotile9.ED.15Mg3(Si2O5)(OH)4
'Clinochrysotile'9.ED.
Diopside9.DA.15CaMgSi2O6
Forsterite9.AC.05Mg2SiO4
Hydroxylclinohumite9.AF.55Mg9(SiO4)4(OH)2
Lizardite9.ED.15Mg3(Si2O5)(OH)4
Unclassified Minerals, Rocks, etc.
'Chlorite Group'-

List of minerals arranged by Dana 8th Edition classification

Group 1 - NATIVE ELEMENTS AND ALLOYS
Metals, other than the Platinum Group
Copper1.1.1.3Cu
Group 6 - HYDROXIDES AND OXIDES CONTAINING HYDROXYL
X(OH)2
Brucite6.2.1.1Mg(OH)2
Group 7 - MULTIPLE OXIDES
AB2X4
Magnetite7.2.2.3Fe2+Fe3+2O4
Group 14 - ANHYDROUS NORMAL CARBONATES
A(XO3)
Calcite14.1.1.1CaCO3
Group 16b - HYDRATED CARBONATES CONTAINING HYDROXYL OR HALOGEN
Pyroaurite16b.6.2.3Mg6Fe3+2(OH)16[CO3] · 4H2O
Group 51 - NESOSILICATES Insular SiO4 Groups Only
Insular SiO4 Groups Only with all cations in octahedral [6] coordination
Forsterite51.3.1.2Mg2SiO4
Insular SiO4 Groups Only with cations in [6] and >[6] coordination
Andradite51.4.3b.1Ca3Fe3+2(SiO4)3
Group 65 - INOSILICATES Single-Width,Unbranched Chains,(W=1)
Single-Width Unbranched Chains, W=1 with chains P=2
Diopside65.1.3a.1CaMgSi2O6
Group 71 - PHYLLOSILICATES Sheets of Six-Membered Rings
Sheets of 6-membered rings with 1:1 layers
Antigorite71.1.2a.1Mg3(Si2O5)(OH)4
Chrysotile71.1.5.1Mg3(Si2O5)(OH)4
'Clinochrysotile'71.1.2d.1
Lizardite71.1.2b.2Mg3(Si2O5)(OH)4
Unclassified Minerals, Mixtures, etc.
Andradite
var: Demantoid
-Ca3Fe3+2(SiO4)3
Aragonite-CaCO3
'Chlorite Group'-
Hydroxylclinohumite-Mg9(SiO4)4(OH)2

List of minerals for each chemical element

HHydrogen
H ChrysotileMg3(Si2O5)(OH)4
H AntigoriteMg3(Si2O5)(OH)4
H LizarditeMg3(Si2O5)(OH)4
H HydroxylclinohumiteMg9(SiO4)4(OH)2
H BruciteMg(OH)2
H PyroauriteMg6Fe23+(OH)16[CO3] · 4H2O
CCarbon
C CalciteCaCO3
C AragoniteCaCO3
C PyroauriteMg6Fe23+(OH)16[CO3] · 4H2O
OOxygen
O ChrysotileMg3(Si2O5)(OH)4
O Andradite (var: Demantoid)Ca3Fe23+(SiO4)3
O AntigoriteMg3(Si2O5)(OH)4
O AndraditeCa3Fe23+(SiO4)3
O LizarditeMg3(Si2O5)(OH)4
O HydroxylclinohumiteMg9(SiO4)4(OH)2
O MagnetiteFe2+Fe23+O4
O BruciteMg(OH)2
O CalciteCaCO3
O AragoniteCaCO3
O PyroauriteMg6Fe23+(OH)16[CO3] · 4H2O
O DiopsideCaMgSi2O6
O ForsteriteMg2SiO4
MgMagnesium
Mg ChrysotileMg3(Si2O5)(OH)4
Mg AntigoriteMg3(Si2O5)(OH)4
Mg LizarditeMg3(Si2O5)(OH)4
Mg HydroxylclinohumiteMg9(SiO4)4(OH)2
Mg BruciteMg(OH)2
Mg PyroauriteMg6Fe23+(OH)16[CO3] · 4H2O
Mg DiopsideCaMgSi2O6
Mg ForsteriteMg2SiO4
SiSilicon
Si ChrysotileMg3(Si2O5)(OH)4
Si Andradite (var: Demantoid)Ca3Fe23+(SiO4)3
Si AntigoriteMg3(Si2O5)(OH)4
Si AndraditeCa3Fe23+(SiO4)3
Si LizarditeMg3(Si2O5)(OH)4
Si HydroxylclinohumiteMg9(SiO4)4(OH)2
Si DiopsideCaMgSi2O6
Si ForsteriteMg2SiO4
CaCalcium
Ca Andradite (var: Demantoid)Ca3Fe23+(SiO4)3
Ca AndraditeCa3Fe23+(SiO4)3
Ca CalciteCaCO3
Ca AragoniteCaCO3
Ca DiopsideCaMgSi2O6
FeIron
Fe Andradite (var: Demantoid)Ca3Fe23+(SiO4)3
Fe AndraditeCa3Fe23+(SiO4)3
Fe MagnetiteFe2+Fe23+O4
Fe PyroauriteMg6Fe23+(OH)16[CO3] · 4H2O
CuCopper
Cu CopperCu

References

Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Sigismund, P. (1948) Granato e vesuvianite in Val Malenco. Atti Soc. It. Sci. Nat., 87, 145-171.
Gramaccioli, C.M. (1962) I minerali valtellinesi nella raccolta di Pietro Sigismund. Ed. privata, Milano, 179 pp.
Bedognè, F. (1970) Località di ritrovamento dei demantoidi. In: Boscardin, M., De Michele, V., Scaini, G. Itinerari mineralogici della Lombardia. Ed. Museo Civ. St. Nat. e Soc. It. Sci. Nat., Milano, 77-80.
Amthauer, G., Kurtz, W., Rost, F., Schloemer, H. (1974) Chemismus und Genese des Andradits aus dem Serpentinit des Val Malenco (Bernina-Gebiet/Oberitalien). Schweiz. Miner. Petr. Mitt., 54, 691-706.
De Michele, V. (1974) Guida mineralogica d'Italia. Ed. De Agostini, Novara, 2 vol., 408 pp.
Gramaccioli, C.M. (1975) Minerali alpini e prealpini. Istituto Italiano Edizioni Atlas, Bergamo, 2 vol., 472 pp.
Bedognè, F. (1979) Itinerari mineralogici. Valmalenco e media Valtellina. Ed. Comunità Montana Valtellina-Ass. Turismo, Sondrio, 63 pp.
Bedognè, F. (1980) Die Mineralien der Grüngesteine des Val Malenco. Lapis, 1980/6, 9-13.
Bedognè, F., and Sciesa, E. (1993) Die Demantoide vom Val Malenco, Sondrio, Italien. Mineralien Welt, 1993/6, 25-28.
Bedognè, F., Montrasio, A., Sciesa, E. (1993) I minerali della provincia di Sondrio: Valmalenco. Bettini, Sondrio, 275 pp.
Bedognè, F., and Sciesa, E. (1994) Asbestklüfte und ihre Mineralien im Serpentinit des Val Malenco (Sondrio, Italien). Mineralienfreund, 1994/4, 13-19.
Benetti, F. (1994) Guida mineralogica della Val Malenco. Grafica Mevio, Sondrio, 203 pp.
Bedognè, F., Sciesa, E., Vignola, P. (1999) Il “demantoide” della Valmalenco. Riv. Miner. It., 23, 4, 208-217.
Bedognè, F., Montrasio, A., Sciesa, E. (2006) I minerali della media-alta Valtellina, delle Orobie valtellinesi e della Val Poschiavo. Aggiornamenti sulle altre località della provincia di Sondrio. Bettini, Sondrio, 255 pp.

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