Carraraite and zaccagnaite, two new minerals from the Carrara marble quarries: their chemical compositions, physical properties, and structural features
-
Stefano Merlino
and
Paolo Orlandi
Abstract
Two new mineral species, carraraite and zaccagnaite, were found in cavities in calcite veins in marble quarries of the Carrara basin (Apuan Alps, Italy). Carraraite, Ca3Ge(OH)6(SO4)1.08 (CO3)0.92⋅12H2O, occurs as submillimetric crystals, tabular on {001}. The cell dimensions are a = 11.056 (3), c = 10.629 (6) Å, and the space group is P63/m. Carraraite is optically uniaxial (-), ω = 1.509, ε = 1.479. The strongest lines of the X-ray diffraction pattern are at d-spacings (Å): 9.57 (vs) (100), 5.53 (s) (110), 3.83 (s) (112), 3.56 (ms) (202), 2.74 (ms) (302). Carraraite is a new member of the ettringite-thaumasite group, which is characterized by columns of composition [Ca3Ge(OH)6 ·12H2O]4+ running along c and interconnected through hydrogen bonding to (SO4)2- and (CO3)2- groups. Zaccagnaite, Zn4Al2(OH)12(CO3)⋅3H2O, occurs as minute hexagonal crystals, elongated parallel to [001]. The cell dimensions are a = 3.0725 (3), c = 15.114 (4) Å and the space group is P63/mmc. The crystals are always covered by a thin crust of fraipontite. The strongest lines of the X-ray diffraction pattern are at d-spacings (Å): 7.51 (vs) (002), 3.794 (m) (004), 1.542 (ms) (108), 1.539 (ms) (110).
Zaccagnaite is a new member of the hydrotalcite-manasseite family; its structure is characterized by a regular alternation of brucite-like layers with composition (Zn2/3Al1/3)(OH)2 and an interlayer composed of carbonate groups and water molecules.
© 2015 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Recalibration of the GASP geobarometer in light of recent garnet and plagioclase activity models and versions of the garnet-biotite geothermometer
- Compositional zoning and element partitioning in nickeloan tourmaline from a metamorphosed karstbauxite from Samos, Greece
- Occurrence of apatite associated with magnetite in an ophiolite complex (Othrys), Greece
- Overpressures induced by coesite-quartz transition in zircon
- Geochemical modeling of bacterially induced mineralization of schwertmannite and jarosite in sulfuric acid spring water
- H2O-D2O exchange in lawsonite
- Composition and temperature dependence of cation ordering in Ni-Mg olivine solid solutions: a time-of-flight neutron powder diffraction and EXAFS study
- Thermal conductivity of spinels and olivines from vibrational spectroscopy: Ambient conditions
- Elasticity of six polycrystalline silicate garnets at pressure up to 3.0 GPa
- The crystal chemistry of birefringent natural uvarovites: Part I. Optical investigations and UV-VIS-IR absorption spectroscopy
- The crystal chemistry of birefringent natural uvarovites: Part II. Single-crystal X-ray structures
- Ferroanthophyllite in Rockport grunerite: A transmission electron microscopy study
- Crystal structure of a new (21)-clinopyribole synthesized at high temperature and pressure
- The Mg(Fe)SiO3 orthoenstatite-clinoenstatite transitions at high pressures and temperatures determined by Raman-spectroscopy on quenched samples
- Raman spectroscopic studies of phase E to 19 GPa
- The crystal structures of the low-temperature phases of leonite-type compounds, K2Me(SO4)2·4H2O (Me2+ = Mg, Mn, Fe)
- Carraraite and zaccagnaite, two new minerals from the Carrara marble quarries: their chemical compositions, physical properties, and structural features
- Pristine surface growth features on 100 Ma garnet phenocrysts: Interference imaging results
- Oxygen triclusters in crystalline CaAl4O7 (grossite) and in calcium aluminosilicate glasses: 17O NMR
- Low-temperature heat capacity of pentlandite
- Calcium segregation at antiphase boundaries in pigeonite
Articles in the same Issue
- Recalibration of the GASP geobarometer in light of recent garnet and plagioclase activity models and versions of the garnet-biotite geothermometer
- Compositional zoning and element partitioning in nickeloan tourmaline from a metamorphosed karstbauxite from Samos, Greece
- Occurrence of apatite associated with magnetite in an ophiolite complex (Othrys), Greece
- Overpressures induced by coesite-quartz transition in zircon
- Geochemical modeling of bacterially induced mineralization of schwertmannite and jarosite in sulfuric acid spring water
- H2O-D2O exchange in lawsonite
- Composition and temperature dependence of cation ordering in Ni-Mg olivine solid solutions: a time-of-flight neutron powder diffraction and EXAFS study
- Thermal conductivity of spinels and olivines from vibrational spectroscopy: Ambient conditions
- Elasticity of six polycrystalline silicate garnets at pressure up to 3.0 GPa
- The crystal chemistry of birefringent natural uvarovites: Part I. Optical investigations and UV-VIS-IR absorption spectroscopy
- The crystal chemistry of birefringent natural uvarovites: Part II. Single-crystal X-ray structures
- Ferroanthophyllite in Rockport grunerite: A transmission electron microscopy study
- Crystal structure of a new (21)-clinopyribole synthesized at high temperature and pressure
- The Mg(Fe)SiO3 orthoenstatite-clinoenstatite transitions at high pressures and temperatures determined by Raman-spectroscopy on quenched samples
- Raman spectroscopic studies of phase E to 19 GPa
- The crystal structures of the low-temperature phases of leonite-type compounds, K2Me(SO4)2·4H2O (Me2+ = Mg, Mn, Fe)
- Carraraite and zaccagnaite, two new minerals from the Carrara marble quarries: their chemical compositions, physical properties, and structural features
- Pristine surface growth features on 100 Ma garnet phenocrysts: Interference imaging results
- Oxygen triclusters in crystalline CaAl4O7 (grossite) and in calcium aluminosilicate glasses: 17O NMR
- Low-temperature heat capacity of pentlandite
- Calcium segregation at antiphase boundaries in pigeonite
