macrocrystalline

... (Brunswick Formation) near Limerick, Pennsylvania. Heretofore attapulgite-palygorskite has been known to occur only in the form of microcrystalline to cryptocrystalline aggregates. The macrocrystalline character of this occurrence is attributed to recrystallization that took place during an episode of mild...

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Journal Article

Kinetics of dehydroxylation and of OH-OD exchange in macrocrystalline micas

Paul G. Rouxhet

Journal: American Mineralogist

Publisher: Mineralogical Society of America

Published: 01 June 1970

American Mineralogist (1970) 55 (5-6): 841–853.

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CL spectra of different agate layers and <span class="search-highlight">macrocrystalline</span> quartz within the...

CL spectra of different agate layers and macrocrystalline quartz within the...

in Characteristics and origin of agates in sedimentary rocks from the Dryhead area, Montana, USA > Mineralogical Magazine

Published: 01 August 2009

F ig . 5. CL spectra of different agate layers and macrocrystalline quartz within the Dryhead agate sample in Fig. 1 a . ( a ) Spectra of different coloured inner agate bands and quartz (compare Figs 3 and 4 ) show similar emission bands with a main CL emission around 650 nm ( b ) Transient

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A. <span class="search-highlight">Macrocrystalline</span> interstitial borax lithofacies. View of layer B (centra...

A. Macrocrystalline interstitial borax lithofacies. View of layer B (centra...

in ZONING IN THE KIRKA BORATE DEPOSIT, WESTERN TURKEY: PRIMARY EVAPORITIC FRACTIONATION OR DIAGENETIC MODIFICATIONS? > The Canadian Mineralogist

Published: 01 August 2004

F ig . 8. A. Macrocrystalline interstitial borax lithofacies. View of layer B (central part of the picture) in the Kırka open-pit mine (Section 2). The top of layer A (lower part of the picture) and the base of layer C (upper part of the picture) can be also observed. Hammer for scale. B

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A. Macrocrystalline interstitial borax lithofacies. View of layer B (centra...

in ZONING IN THE KIRKA BORATE DEPOSIT, WESTERN TURKEY: PRIMARY EVAPORITIC FRACTIONATION OR DIAGENETIC MODIFICATIONS? > The Canadian Mineralogist

Published: 01 August 2004

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The increasing crystallinity is shown by the sharpening of the 212, 203 and...

in Metamorphic effects on agate found near the Shap granite, Cumbria, England: as demonstrated by petrography, X-ray diffraction and spectroscopic methods > Mineralogical Magazine

Published: 01 August 2007

F ig . 3. The increasing crystallinity is shown by the sharpening of the 212, 203 and 301 reflections in agate and macrocrystalline quartz. Locality and age of host: a: Brazilian macrocrystalline quartz reference; b: Warrawoona, Western Australia (3.48 Ga); c: Stockdale Beck, England (430 Ma); d

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$Diffractograms from various samples with moganite and quartz peaks labelled...$

Diffractograms from various samples with moganite and quartz peaks labelled...

in Moganite and water content as a function of age in agate : an XRD and thermogravimetric study > European Journal of Mineralogy

Published: 01 March 2004

%) and 5) macrocrystalline quartz. Note the decrease in the moganite peaks, and the simultaneous increase in the quartz peaks. The shaded background is due to the presence of amorphous silica. The dotted line corresponds to a macrocrystalline quartz sample.

Journal Article

Characteristics and origin of agates in sedimentary rocks from the Dryhead area, Montana, USA

J. Götze, R. Möckel, U. Kempe, I. Kapitonov, T. Vennemann

Journal: Mineralogical Magazine

Publisher: Mineralogical Society of Great Britain and Ireland

Published: 01 August 2009

Mineralogical Magazine (2009) 73 (4): 673–690.

DOI: https://doi.org/10.1180/minmag.2009.073.4.673

...F ig . 5. CL spectra of different agate layers and macrocrystalline quartz within the Dryhead agate sample in Fig. 1 a . ( a ) Spectra of different coloured inner agate bands and quartz (compare Figs 3 and 4 ) show similar emission bands with a main CL emission around 650 nm ( b ) Transient...

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Block LJB006. The color sequence containing the greenish quartz nucleated o...

in GREENISH QUARTZ FROM THE THUNDER BAY AMETHYST MINE PANORAMA, THUNDER BAY, ONTARIO, CANADA > The Canadian Mineralogist

Published: 01 February 2008

F ig . 1. Block LJB006. The color sequence containing the greenish quartz nucleated on brecciated fragments and consists of (1) reddish chalcedony, (2) macrocrystalline quartz grading from colorless to greenish gray over 2.0 ± 0.5 cm, (3) a fine (0.5 ± 0.2 cm) layer of white chalcedony, (4

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Textures of facies 2 ores (optical microscopy, transmitted light). A) sampl...

in Genesis of the Florida Canyon Nonsulfide Zn Ores (Northern Peru): New Insights Into the Supergene Mineralizing Events of the Bongará District > Economic Geology

Published: 01 September 2022

Fig. 7. Textures of facies 2 ores (optical microscopy, transmitted light). A) sample V311-B – macrocrystalline smithsonite containing rare euhedral quartz crystals (N + ); B) sample V311-CAN – fine-grained gray smithsonite with coarser crystals precipitating in fractures (NII); C) sample V436

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Field appearance of palygorskite-bearing veins, in arkosic Inkisi Subgroup ...

in Palygorskite-bearing fracture fills in the Kinshasa area, DR Congo – an exceptional mode of palygorskite vein development > South African Journal of Geology

Published: 01 June 2019

quarry). ( C ) Vein in horizontal exposure along the Congo River, as part of a northeast-trending left-lateral strike-slip fracture system, including a lens with abundant fragments of macrocrystalline calcite infillings (Kinsuka area). ( D ) Macrocrystalline calcite in extension fractures without lateral

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Calcite veins. ( A ) Fine-granular calcite with common pressure twinning (a...

in Palygorskite-bearing fracture fills in the Kinshasa area, DR Congo – an exceptional mode of palygorskite vein development > South African Journal of Geology

Published: 01 June 2019

macrocrystalline calcite coatings in a closed fracture (RGM 16847, XPL). ( F ) Palygorskite without alignment of clay aggregates and with scattered microsparitic calcite, along the surface of a macrocrystalline calcite coating in an open fracture (RGM 16850, XPL).

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Optical micrographs: (a) panoramic picture of the AQ_01 aquaprase sample; a...

in Similarities and differences among selected gemmological varieties of chalcedony: chemistry, mineralogy and microstructure > Mineralogical Magazine

Published: 01 April 2024

Figure 2. Optical micrographs: (a) panoramic picture of the AQ_01 aquaprase sample; and (b) details: fibrous quartz between cryptocrystalline and microcrystalline quartz (XPL, grey scale). Mineral abbreviations (Warr, 2021 ): MQz: macrocrystalline quartz; mQz: microcrystalline quartz; cQz

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Common diagenetic processes occurring in stevensite rocks. A) Early cemen...

in Depositional and diagenetic processes in the pre-salt rift section of a Santos Basin area, SE Brazil > Journal of Sedimentary Research

Published: 26 June 2020

Fig. 10.— Common diagenetic processes occurring in stevensite rocks. A) Early cementation by microcrystalline quartz and replacement of ooids by dolomite (XP). B) Macrocrystalline calcite as interparticle cement (yellow arrow) and replacing ooids (green arrows), dolomite replacing ooids (blue

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Diagenetic processes occurring at rift carbonate rocks. A) Preserved grow...

in Depositional and diagenetic processes in the pre-salt rift section of a Santos Basin area, SE Brazil > Journal of Sedimentary Research

Published: 26 June 2020

pores are lined by prismatic calcite rims and filled by macrocrystalline quartz. Calcite stained pink (XP). F) Fracture and moldic porosity from dissolution of bivalve bioclasts cemented by quartz (//P). G) Cathodoluminescence image showing macrocrystalline calcite filling fractures cutting

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–Thin-section photomicrographs illustrating selected diagenetic products an...

in A Predictive Model for Reservoir Distribution in the Permian (Leonardian) Clear Fork and Glorieta Formations, Robertson Field Area, West Texas > AAPG Bulletin

Published: 01 July 1999

micrite envelope in southwest portion of photomicrograph) (4), grain leaching (6), macrocrystalline dolomitization (5), and anhydrite cementation (7). Robertson Clear Fork unit 19-03, 2051.0 m (6729 ft). (C) Macrocrystalline dolomite crystals sutured along a stylolite surface (8). Robertson Clear Fork

Journal Article

Palygorskite-bearing fracture fills in the Kinshasa area, DR Congo – an exceptional mode of palygorskite vein development

F. Mees, R. Adriaens, A. Delgado-Huertas, D. Delvaux, P. Lahogue, C. Mpiana, L. Tack

Journal: South African Journal of Geology

Publisher: Geological Society of South Africa

Published: 01 June 2019

South African Journal of Geology (2019) 122 (2): 173–186.

DOI: https://doi.org/10.25131/sajg.122.0013

... quarry). ( C ) Vein in horizontal exposure along the Congo River, as part of a northeast-trending left-lateral strike-slip fracture system, including a lens with abundant fragments of macrocrystalline calcite infillings (Kinsuka area). ( D ) Macrocrystalline calcite in extension fractures without lateral...

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Journal Article

Low-Crystallinity Index Chalcedony from Longhua, China: Characteristics and Formation

Qiuli Yan, Guanghai Shi

Journal: Lithosphere

Publisher: GSW

Published: 10 August 2023

Lithosphere (2023) 2023 (1): 2061776.

DOI: https://doi.org/10.2113/2023/2061776

... of 1.97%–2.32% by heating. From the boundary to the inner center, its growth structure changes from comb-like macrocrystalline quartz to thin fiber crystallites and then to a relatively uniform cryptocrystalline phase, indicating precipitation from a crystalline to the cryptocrystalline sequence. Electron...

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