Ramanite-(Cs) and ramanite-(Rb): New cesium and rubidium pentaborate tetrahydrate minerals identified with Raman spectroscopy
-
Rainer Thomas
,
Paul Davidson
Abstract
This study of melt and fluid inclusions in graphic pegmatite quartz from the Island of Elba, Italy has identified silicate melts and coexisting aqueous fluid from the final stage of pegmatite formation, which contain extremely high concentrations of boron (up to 19.8 mass% B2O3), cesium (>5 mass% Cs2O), and rubidium (>0.5 mass% Rb2O). Several boron-bearing minerals have been identified in melt and fluid inclusions, including sassolite (H3BO3) and santite (KB5O8·4H2O). In addition, we have found two new minerals observed as daughter mineral phases, and these have been accepted by the IMA, Commission on New Minerals, Nomenclature and Classification (CNMNC) as ramanite-(Cs) (2007-007), monoclinic β-cesium pentaborate tetrahydrate (CsB5O8·4H2O) with space group C2/c, and ramanite-(Rb) (2007-006), orthorhombic rubidium pentaborate tetrahydrate (RbB5O8·4H2O) with space group Aba2. At the moment, given sample constraints, we cannot directly determine some of the properties traditionally reported for new minerals; however, both phases have Raman spectra identical to spectra obtained on synthetic Cs and Rb pentaborates, which were studied for comparison. Although difficult to recognize optically, ramanite-(Cs) and ramanite-(Rb) have distinctive Raman spectra allowing simple and definitive identification from other translucent phases found in many hypersaline fluid inclusions. Although currently only identified from a limited number of occurrences, given the availability of a definitive means of identification, we suspect that ramanite-(Rb) and ramanite-(Cs) may in fact be common, at least in boron-rich pegmatites.
© 2015 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Rietveld structure refinement of MgGeO3 post-perovskite phase to 1 Mbar
- High-temperature ammonium white mica from the Betic Cordillera (Spain)
- Synthesis and crystal structure of the feldspathoid CsAlSiO4: An open-framework silicate and potential nuclear waste disposal phase
- The crystal chemistry of Li in gadolinite
- The effect of the hedenbergitic substitution on the compressibility of jadeite
- The structure of monohydrocalcite and the phase composition of the beachrock deposits of Lake Butler and Lake Fellmongery, South Australia
- First-principles calculation of the infrared spectrum of hematite
- In situ observations of muscovite dissolution under alkaline conditions at 25–50 °C by AFM with an air/fluid heater system
- Ramanite-(Cs) and ramanite-(Rb): New cesium and rubidium pentaborate tetrahydrate minerals identified with Raman spectroscopy
- Pressure-temperature studies of talc plus water using X-ray diffraction
- Hematite and magnetite precipitates in olivine from the Sulu peridotite: A result of dehydrogenation-oxidation reaction of mantle olivine?
- Arsenide in a metasomatized peridotite xenolith as a constraint on arsenic behavior in the mantle wedge
- Multiple oxygen sites in synthetic phyllosilicates with expandable layers: 17O solid-state NMR study
- On the existence of a Na-deficient monoclinic trinepheline with composition Na7.85Al7.85Si8.15O32
- Chlorite and biotite weathering, Fe2+-rich corrensite formation, and Fe behavior under low Po₂ conditions and their implication for Precambrian weathering
- Structural characterization of natural UO2 at pressures up to 82 GPa and temperatures up to 2200 K
- Dense hydrous magnesium silicates, phase D, and superhydrous B: New structural constraints from one- and two-dimensional 29Si and 1H NMR
- Mid-IR bands of synthetic calcic amphiboles of tremolite-pargasite series and of natural calcic amphiboles
- Probing the site occupancies of Co-, Ni-, and Mn-substituted biogenic magnetite using XAS and XMCD
- Origin of titanite in metarodingite from the Zagros Thrust Zone, Iraq
- Experimental calibration of aluminum partitioning between olivine and spinel as a geothermometer
- Single-crystal X-ray diffraction study of CaIrO3
- Orthorhombic polymorph of rengeite from Ohmi region, central Japan
- New insights into the crystal chemistry of epididymite and eudidymite from Malosa, Malawi: A single-crystal neutron diffraction study
- Mechanisms of rhyolitic glass hydration below the glass transition
- Heat capacity and entropy of melanophlogite: Molecule-containing porosils in nature
- Crystal structure of glaucodot, (Co,Fe)AsS, and its relationships to marcasite and arsenopyrite
- Modification of gas speciation in quartz-hosted fluid inclusions by stray laser radiation during LA-ICPMS analysis
- A PH₂O-dependent structural phase transition in the zeolite natrolite
Articles in the same Issue
- Rietveld structure refinement of MgGeO3 post-perovskite phase to 1 Mbar
- High-temperature ammonium white mica from the Betic Cordillera (Spain)
- Synthesis and crystal structure of the feldspathoid CsAlSiO4: An open-framework silicate and potential nuclear waste disposal phase
- The crystal chemistry of Li in gadolinite
- The effect of the hedenbergitic substitution on the compressibility of jadeite
- The structure of monohydrocalcite and the phase composition of the beachrock deposits of Lake Butler and Lake Fellmongery, South Australia
- First-principles calculation of the infrared spectrum of hematite
- In situ observations of muscovite dissolution under alkaline conditions at 25–50 °C by AFM with an air/fluid heater system
- Ramanite-(Cs) and ramanite-(Rb): New cesium and rubidium pentaborate tetrahydrate minerals identified with Raman spectroscopy
- Pressure-temperature studies of talc plus water using X-ray diffraction
- Hematite and magnetite precipitates in olivine from the Sulu peridotite: A result of dehydrogenation-oxidation reaction of mantle olivine?
- Arsenide in a metasomatized peridotite xenolith as a constraint on arsenic behavior in the mantle wedge
- Multiple oxygen sites in synthetic phyllosilicates with expandable layers: 17O solid-state NMR study
- On the existence of a Na-deficient monoclinic trinepheline with composition Na7.85Al7.85Si8.15O32
- Chlorite and biotite weathering, Fe2+-rich corrensite formation, and Fe behavior under low Po₂ conditions and their implication for Precambrian weathering
- Structural characterization of natural UO2 at pressures up to 82 GPa and temperatures up to 2200 K
- Dense hydrous magnesium silicates, phase D, and superhydrous B: New structural constraints from one- and two-dimensional 29Si and 1H NMR
- Mid-IR bands of synthetic calcic amphiboles of tremolite-pargasite series and of natural calcic amphiboles
- Probing the site occupancies of Co-, Ni-, and Mn-substituted biogenic magnetite using XAS and XMCD
- Origin of titanite in metarodingite from the Zagros Thrust Zone, Iraq
- Experimental calibration of aluminum partitioning between olivine and spinel as a geothermometer
- Single-crystal X-ray diffraction study of CaIrO3
- Orthorhombic polymorph of rengeite from Ohmi region, central Japan
- New insights into the crystal chemistry of epididymite and eudidymite from Malosa, Malawi: A single-crystal neutron diffraction study
- Mechanisms of rhyolitic glass hydration below the glass transition
- Heat capacity and entropy of melanophlogite: Molecule-containing porosils in nature
- Crystal structure of glaucodot, (Co,Fe)AsS, and its relationships to marcasite and arsenopyrite
- Modification of gas speciation in quartz-hosted fluid inclusions by stray laser radiation during LA-ICPMS analysis
- A PH₂O-dependent structural phase transition in the zeolite natrolite
