TEM imaging and analysis of microinclusions in diamonds: A close look at diamond-growing fluids
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Ofra Klein-BenDavid
,
Richard Wirth
Abstract
Fluid-bearing microinclusions in diamonds (<1 μm) provide a unique source of information on the diamond-forming medium. Transmission electron microscopy (TEM) investigation of such microinclusions enables the detailed study of their size, external habit, internal morphology, and mineralogy, and yields information on the chemical composition and crystallography of the included phases. Here we present a detailed TEM examination of microinclusions in four fibrous diamonds from Canada and Siberia, each with a distinctive inferred original fluid composition. Most microinclusions contain multi-phase assemblages that include carbonate, halide, apatite, possible pyroxene, and high-silica mica (6.8-7.7 Si atoms per formula unit) whose composition lies along the phlogopite-Al-celadonite join. The TEM results, together with the tight range of composition detected by electron probe microanalysis (EPMA) and the volatiles detected by infrared (IR) spectroscopy, suggest that the microinclusions trapped a uniform, dense, supercritical fluid and that the crystallized minerals grew as secondary phases during cooling.
Carbonates appear in all assemblages, together with either halides or silicates, indicative of the importance of carbonatitic high-density fluid during diamond growth and fluid evolution. The presence of halide-carbonate or silicate-carbonate assemblages is in agreement with the bulk composition of the microinclusions as detected by EPMA. The high K content of some microinclusions detected by EPMA cannot be accounted for by the solid phases analyzed by TEM. This discrepancy suggests that K is concentrated in the residual fluid that is lost during TEM sample preparation. In addition to microinclusions, large cavities containing amorphous phases were found in the inner parts of one Siberian and one Canadian diamond. An Al-rich phase is the most abundant, and it is accompanied by Ca-rich and Si-rich phases. These phases may be explained by amorphization of crystalline phases. A breakdown of a single melt into three immiscible components is less likely.
© 2015 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Presidential Address: Elastic properties of minerals and the influence of phase transitions
- Pressure-induced hydration in zeolite tetranatrolite
- Annealing experiments on induced fission tracks in apatite: Measurements of horizontal-confined track lengths and track densities in basal sections and randomly oriented grains
- Alpersite (Mg,Cu)SO4·7H2O, a new mineral of the melanterite group, and cuprian pentahydrite: Their occurrence within mine waste
- Application of a new vanadium valence oxybarometer to basaltic glasses from the Earth, Moon, and Mars
- Quantitative polarized infrared analysis of trace OH in populations of randomly oriented mineral grains
- Hydrogen incorporation in olivine from 2–12 GPa
- A numerical model for steady-state temperature distributions in solid-medium high-pressure cell assemblies
- Thermodynamics and kinetics of cation ordering in natural and synthetic Mg(Al,Fe3+)2O4 spinels from in situ high-temperature X-ray diffraction
- Kinetics of cation ordering in natural Mg(Al,Cr3+)2O4 spinels
- Equations of state and structures of andalusite to 9.8 GPa and sillimanite to 8.5 GPa
- Equation of state and phase transition in KAlSi3O8 hollandite at high pressure
- A novel arrangement of silicate tetrahedra in the uranyl silicate sheet of oursinite, (Co0.8Mg0.2)[(UO2)(SiO3OH)]2(H2O)6
- Aluminum substitution in stishovite and MgSiO3 perovskite: High-resolution 27Al NMR
- The effect of chlorine on the viscosity of Na2O-Fe2O3-Al2O3-SiO2 melts
- TEM imaging and analysis of microinclusions in diamonds: A close look at diamond-growing fluids
- A partial molar volume for ZnO in silicate melts
- Garnet-spinel intergrowths in ultrahigh-temperature granulite, Eastern Ghats, India: Possible evidence of an early Tschermak-rich orthopyroxene during prograde metamorphism
- The partial molar volume of Fe2O3 in alkali silicate melts: Evidence for an average Fe3+ coordination number near five
- The crystal structure of a second antigorite polysome (m = 16), by single-crystal synchrotron diffraction
- Oxide melt solution calorimetry of sulfides: Enthalpy of formation of sphalerite, galena, greenockite, and hawleyite
- An experimental determination of the effect of pressure on the Fe3+/ΣFe ratio of an anhydrous silicate melt to 3.0 GPa
- Evolution of product phase assemblages during thermal decomposition of muscovite under strong disequilibrium conditions
- Synthetic P21/m amphiboles in the system Li2O-Na2O-MgO-SiO2-H2O (LNMSH)
- Incongruent dissolution of wollastonite measured with vertical scanning interferometry
- Experiments on CaCO3-MgCO3 solid solutions at high pressure and temperature
- Calorimetric data for naturally occurring magnesiocarpholite and ferrocarpholite
- Clinopyroxene exsolution in wollastonite from Namaqualand granulite, South Africa
- Icosahedral coordination of phosphorus in the crystal structure of melliniite, a new phosphide mineral from the Northwest Africa 1054 acapulcoite
- Mechanism for the dissolution of olivine series minerals in acidic solutions
- High-pressure behavior of synthetic antigorite in the MgO-SiO2-H2O system from Raman spectroscopy
- Sinoite (Si2N2O) shocked at pressures of 28 to 64 GPa
- Laser Raman spectroscopic measurements of water in unexposed glass inclusions
- The Mars/Earth dichotomy in Mg/Si and Al/Si ratios: Is it real?
- Equation of state of CaIrO3-type MgSiO3 up to 144 GPa
- Synchrotron infrared spectroscopy of synthetic Na(NaMg)Mg5Si8O22(OH)2 up to 30 GPa: Insight on a new high-pressure amphibole polymorph
Articles in the same Issue
- Presidential Address: Elastic properties of minerals and the influence of phase transitions
- Pressure-induced hydration in zeolite tetranatrolite
- Annealing experiments on induced fission tracks in apatite: Measurements of horizontal-confined track lengths and track densities in basal sections and randomly oriented grains
- Alpersite (Mg,Cu)SO4·7H2O, a new mineral of the melanterite group, and cuprian pentahydrite: Their occurrence within mine waste
- Application of a new vanadium valence oxybarometer to basaltic glasses from the Earth, Moon, and Mars
- Quantitative polarized infrared analysis of trace OH in populations of randomly oriented mineral grains
- Hydrogen incorporation in olivine from 2–12 GPa
- A numerical model for steady-state temperature distributions in solid-medium high-pressure cell assemblies
- Thermodynamics and kinetics of cation ordering in natural and synthetic Mg(Al,Fe3+)2O4 spinels from in situ high-temperature X-ray diffraction
- Kinetics of cation ordering in natural Mg(Al,Cr3+)2O4 spinels
- Equations of state and structures of andalusite to 9.8 GPa and sillimanite to 8.5 GPa
- Equation of state and phase transition in KAlSi3O8 hollandite at high pressure
- A novel arrangement of silicate tetrahedra in the uranyl silicate sheet of oursinite, (Co0.8Mg0.2)[(UO2)(SiO3OH)]2(H2O)6
- Aluminum substitution in stishovite and MgSiO3 perovskite: High-resolution 27Al NMR
- The effect of chlorine on the viscosity of Na2O-Fe2O3-Al2O3-SiO2 melts
- TEM imaging and analysis of microinclusions in diamonds: A close look at diamond-growing fluids
- A partial molar volume for ZnO in silicate melts
- Garnet-spinel intergrowths in ultrahigh-temperature granulite, Eastern Ghats, India: Possible evidence of an early Tschermak-rich orthopyroxene during prograde metamorphism
- The partial molar volume of Fe2O3 in alkali silicate melts: Evidence for an average Fe3+ coordination number near five
- The crystal structure of a second antigorite polysome (m = 16), by single-crystal synchrotron diffraction
- Oxide melt solution calorimetry of sulfides: Enthalpy of formation of sphalerite, galena, greenockite, and hawleyite
- An experimental determination of the effect of pressure on the Fe3+/ΣFe ratio of an anhydrous silicate melt to 3.0 GPa
- Evolution of product phase assemblages during thermal decomposition of muscovite under strong disequilibrium conditions
- Synthetic P21/m amphiboles in the system Li2O-Na2O-MgO-SiO2-H2O (LNMSH)
- Incongruent dissolution of wollastonite measured with vertical scanning interferometry
- Experiments on CaCO3-MgCO3 solid solutions at high pressure and temperature
- Calorimetric data for naturally occurring magnesiocarpholite and ferrocarpholite
- Clinopyroxene exsolution in wollastonite from Namaqualand granulite, South Africa
- Icosahedral coordination of phosphorus in the crystal structure of melliniite, a new phosphide mineral from the Northwest Africa 1054 acapulcoite
- Mechanism for the dissolution of olivine series minerals in acidic solutions
- High-pressure behavior of synthetic antigorite in the MgO-SiO2-H2O system from Raman spectroscopy
- Sinoite (Si2N2O) shocked at pressures of 28 to 64 GPa
- Laser Raman spectroscopic measurements of water in unexposed glass inclusions
- The Mars/Earth dichotomy in Mg/Si and Al/Si ratios: Is it real?
- Equation of state of CaIrO3-type MgSiO3 up to 144 GPa
- Synchrotron infrared spectroscopy of synthetic Na(NaMg)Mg5Si8O22(OH)2 up to 30 GPa: Insight on a new high-pressure amphibole polymorph
