Phengite hosts Cs, Rb and Ba (Supplementary Fig. 5) and, at the beginning of its destabilization, Cs preferentially partition to the fluid whereas Ba remains in phengite until its complete ...
At first glance, this specimen of "Phengite" (a series between Muscovite and Celadonite) is an ordinary Mica crystal, but when strongly backlit, and viewed from the side, one can see the most intense internal blue-green color. This is a most surprising specimen considering that Mica is rarely colorful, let alone has such a vibrant hue like this ...
In our two paleosubduction settings, the grain-, sample-, and locality-scale age relationships of phengite within eclogite and related rocks document protracted time …
The near- and mid-infrared reflectance spectroscopy of phengite can provide valuable information about phengite abundance and phengite mineral chemistry (Mookherjee and Redfern, 2002). For example, we …
Phengite is a common metamorphic mineral stable in a wide pressure range. The dependence of pressure on silicon content established in the mid-20th century allowed us to propose a phengite-based geobarometer. Recently, the phengite geobarometer was calibrated by Caddik and Thompson (2008) but in the narrow …
a natural phengite sample collected from schist. Phengite is a common hydrous mineral in UHP eclogites from orogenic belts (e.g., Nakamura 2003; Poli and Schmidt 1997). Studying the high-pressure and high-temperature properties of phengite can help to better understand the transportation and release of water in continental slabs dur -
The petrography and phengite chemistry by electron probe micro-analyzer (EPMA) revealed the existence of detrital white micas in the schist that have an extremely older age (108 …
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The Correlation Between Raman Spectra and the Mineral Composition of Muscovite and Phengite. Huijuan Li, ... Andrew G. Christy, in Ultrahigh-Pressure Metamorphism, 2011 7.1 Introduction. Phengite is a series name for muscovite–celadonite solid solutions, KAl 2 [AlSi 3 O 10](OH) 2 K(Mg, Fe 2+)(Al, Fe 3+)[Si 4 O 10](OH) 2.Celadonite sensu stricto has …
Semantic Scholar extracted view of "Phengite micas; synthesis, stability, and natural occurrence" by B. Velde
Following and extending the early work of Velde (1965) the pressure-temperature dependence of the compositions of potassic white micas coexisting with K-feldspar, quartz, and phlogopite in the model system K2O-MgO-Al2O3-SiO2-H2O was investigated up to fluid pressures of 24 kbar by synthesis experiments. There is a strong, almost linear …
7.1. Introduction. Phengite is a series name for muscovite–celadonite solid solutions, KAl 2 [AlSi 3 O 10](OH) 2 K(Mg, Fe 2+)(Al, Fe 3+)[Si 4 O 10](OH) 2.Celadonite sensu stricto has Mg and Fe 3+ dominant over Fe 2+ and Al. The other siliceous endmembers are aluminoceladonite, ferroceladonite, and ferroaluminoceladonite …
The Samana Metamorphic Complex contains eclogite blocks produced during subduction of the North American plate beneath the Caribbean plate (supporting online text) (7, 8).Glaucophane Sm/Nd …
The Ishigaki high-pressure schist belt in the southern Ryukyu Arc is correlated with the Suo high-pressure schist belt in southwest Japan. The former metamorphic sequence is composed mainly of basic and pelitic schists and is subdivided into three zones, the lower-grade zone A, the medium-grade zone B and the high-grade …
PDF | On Sep 1, 2013, Michelle C. Tappert and others published The mineral chemistry, near-infrared, and mid-infrared reflectance spectroscopy of phengite from the Olympic Dam IOCG deposit, South ...
Field relations and the presence of UHP minerals such as coesite, omphacite and high-Si phengite in the eclogites and the enclosing calc-silicates testify to a common metamorphic evolution for these two lithologies. Except for one sample, all bear phengite with unusually high silica contents (Si up to 3.7 per formula unit).
The Si content of phengite in subsolidus mineral assemblages at 4 GPa is between 3.45 and 3.5 pfu at 4 GPa, and around 3.65 pfu at 9 GPa, higher than the initial Si content of phengite in the eclogitic starting material (Si = 3.4-3.45 pfu). After crossing the solidus curve, phengite dehydration melting occurs as phengite is the first phase that ...
Phengite was found to coexist with garnet, kyanite, topaz, stishovite, and jadeite in high-pressure and high-temperature experiments from 5.5 to 11 GPa at 900 °C …
Phengite is an aluminous true mica which contains a relatively high amount of tetrahedrally co-ordinated Si (>3.1 apfu). As the Si amount increases, additional …
Phengite meltingrdissolution occurs between 9008C and 9758C at 6.5–8 GPa and is associated with the appearance of kyanite in the phase assemblage. The formation of K-hollandite is accompanied by ...
Phengite is a common hydrous phase in K-Al-bearing HP-UHP marbles and generally shows a flaky morphology (e.g., Guo et al., 2019; Kato et al., 1997); Liu et al., …
Highlights We identified two compositionally distinct types of phengite at Olympic Dam. Phengites from ore-bearing rocks have low Si, high Al, and a low Mg-number. Phengites around the deposit halo have high Si, low Al, and a high Mg-number. Compositional differences are observed in near- and mid-infrared reflectance spectra. …
Stability of phengite and biotite in eclogite is discussed using petrological data of natural eclogites, and the observational data are examined by thermodynamic calculations. Generally, phengite is a major K phase in natural eclogite and is stable in wide range of bulk composition. However, in eclogites from several localities of the …
Phengite is developed along the penetrative foliation planes in the eclogite. ... Whole-rock samples were crushed in a corundum jaw crusher (to 60 meshes). About 60 g of each sample was powered in ...
Phengite is a common hydrous phase in K-Al-bearing HP-UHP marbles and generally shows a flaky morphology (e.g., Guo et al., 2019; Kato et al., 1997); Liu et al., 2015). This mineral controls the fluid budget and mobilization of fluid-mobile elements, such as B, Cs, Rb, and Ba, in marbles. The flaky shape and mineral assemblage (Pl + Bt ± …
Phengite melting occurs between 1075-1150°C at 7-8 GPa and 1000-1050°C at 10 GPa. At 10-11 GPa, 800°C octahedral cation deficient (OCD) muscovite and K-hollandite are observed rather than phengite. The average phengite content of muscovite is positively correlated with pressure ranging from 3.65 Si pfu at 5.5 GPa to 3.81 Si pfu …
Additionally, biotite and phengite in equilibrium with granitic melts preferentially incorporate Nb over Ta. Therefore incipient partial melting of biotite-rich crustal rocks produces restites with high Nb/Ta. Progressive melting of such rocks leads to the consumption of biotite and the formation of peritectic rutile or ilmenite, which retain ...
The granitoid is altered to a low-grade association consisting of Mg-Fe- chlorite (ripidolite type), quartz, albite (Ab 99-100 ), phengite, and zoisite (Figs. 5, 6 and 7), with accessory minerals ...
In our proposed mechanism of ammonium loss from phengite (Yang et al., 2017), hydrogen of ammonium separates from nitrogen and forms OH bound with …
Alurgite is the old name for pink Mn-rich muscovite and phengite (Breithaupt 1865; Meixner 1939).In their nomenclature of the micas, Rieder et al. suggest that the term alurgite should be abandoned in favor of the term manganoan muscovite or phengite.However, since manganese in these micas is mostly Mn 3+ instead of Mn 2+ …
With the appearance of phengite, the amount of preserved intergranular coesite is obviously reduced. Phengite is developed along the penetrative foliation …
Phengite series is a dioctahedral solid solution between two end-members of muscovite [K1[Al2]VI[Al1,Si3]IVO10(OH)2] and celadonite [K1[(Fe3+,Al)1,(Mg,Fe2+)1]VI[Si4]IVO10(OH)2], which have a hetero-valent substitution of AlVIAlIV ↔ (Mg, Fe)VISiIV. In this study, we report a hydrothermal-originated authigenic …
Phengite chemistry has been investigated in experiments on a natural SiO2–TiO2-saturated greywacke and a natural SiO2–TiO2–Al2SiO5-saturated pelite, at 1.5–8.0 GPa and 800–1,050°C. High Ti-contents (0.3–3.7 wt %), Ti-enrichment with temperature, and a strong inverse correlation of Ti-content with pressure are the …
The samples were crushed with a jaw crusher and then sieved. Phengite was separated from the 80–100, 100–150, 150–200, or 200–250 mesh size fractions of the samples. ... In contrast, the phengite included in rigid garnet, which has a high Si value, does not release Ar, as documented by Gouzu et al. (2006). They revealed that the ...
