TY - JOUR
T1 - Chiavennite, CaMnBe2Si5O13(OH)2.2H2O, a new mineral from Chiavenna (Italy)
AU - Bondi, M.
AU - Griffin, W. L.
AU - Mattioli, V.
AU - Mottana, A.
PY - 1983
Y1 - 1983
N2 - Chiavennite, named for its type locality, occurs as euhedral orange grains and as crusts coating beryl in the Alpine pegmatites crossing the Chiavenna ultramafics in the Rhaetic Alps of Italy. With ideal formula CaMnBe2Si5O13(OH)2.2H2O, chiavennite is optically biaxial and orthorhombic: P21ab, a 8.729(5), b 31.326(11), c 4.903(2) A, Z = 4, with Dcalc. 2.657 g/cm3, Dmeas. 2.64(1) g/cm3; alpha (colourless to pale yellow) 1.581(1), gamma (yellow-orange) 1.600(1). The most intense powder XRD reflections are: 15.7(100), 2.903(100), 3.28(75), 4.15(30), 3.93(30), 3.82(30), 1.944(30) A. Chiavennite appears to form in association with bavenite and other pegmatitic minerals as the result of late-phase fluid activity in pegmatites. (A.M. 68-628)-J.A.Z.
AB - Chiavennite, named for its type locality, occurs as euhedral orange grains and as crusts coating beryl in the Alpine pegmatites crossing the Chiavenna ultramafics in the Rhaetic Alps of Italy. With ideal formula CaMnBe2Si5O13(OH)2.2H2O, chiavennite is optically biaxial and orthorhombic: P21ab, a 8.729(5), b 31.326(11), c 4.903(2) A, Z = 4, with Dcalc. 2.657 g/cm3, Dmeas. 2.64(1) g/cm3; alpha (colourless to pale yellow) 1.581(1), gamma (yellow-orange) 1.600(1). The most intense powder XRD reflections are: 15.7(100), 2.903(100), 3.28(75), 4.15(30), 3.93(30), 3.82(30), 1.944(30) A. Chiavennite appears to form in association with bavenite and other pegmatitic minerals as the result of late-phase fluid activity in pegmatites. (A.M. 68-628)-J.A.Z.
UR - http://www.scopus.com/inward/record.url?scp=0021061589&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0021061589
SN - 0003-004X
VL - 68
SP - 623
EP - 627
JO - American Mineralogist
JF - American Mineralogist
IS - 5-6
ER -