bluuebunny/crossref_metadata_2025 huggingface dataset:
Root penetration through sealing layers at mine deposit sites
Authors: Stoltz Eva , Greger Maria
Published: December 2006

To prevent acid mine drainage arising from oxygen and water penetration of sulphide-rich mine tailings, the tailings are covered with layers of dry sealing material. Plant roots have a great ability to penetrate dense materials, and if the roots are able to penetrate the sealing layer of a tailings deposit, its oxygen-shielding properties could be reduced. The objective of this study was to evaluate whether plant roots are able to penetrate sealing layers covering mine tailings deposits. Root penetration into layers of various sealing materials, such as clayey moraine (clay, 8-10%; silt, 22-37%; sand, 37-55%; gravel, 15-18%), moraine (unspecified), 6-mm bentonite (kaolin clay) fabric, lime and clay, Cefyll® (mixture of pulverized coal fly ash, cement and water) and a mixture containing biosludge (30-35%) and bioashes (65-70%), was investigated. In the field, roots were studied by digging trenches alongside vegetation growing in 3- and 10-year-old mine sites. In the greenhouse root growth of Betula pendula, Pinus sylvestris, Poa pratensis and Salix viminalis were studied in compartments where the plants had been growing for 22 months. The results from the field experiment indicated that roots are able to penetrate both deep down in the cover layer (1.7 m) and also into the sealing layers of various materials, and even to penetrate hard Cefyll. The addition of nutrients in the top cover reduced deep root growth and thereby also penetration through the sealing layer. Low hydraulic conductivity of the sealing layer or a thick cover layer had less effect on root penetration. In the greenhouse experiment roots did not penetrate the thin bentonite fabric, due to low pH (2.1-2.7) that was created from the underlying weathered mine tailings. The clayey moraine was penetrated by all species used in the greenhouse experiment; Pinus sylvestris had the greatest ability to penetrate. To prevent root penetration of the other sealing layer, a suitable condition for the plants should be created in the upper part of the cover layer, namely a sufficient amount of plant nutrients. However, to define such a condition is difficult since different plant species have different requirements.
Lysimeter comparison of the role of waste characteristics in the formation of mineral deposits in leachate drainage systems
Authors: Cardoso Antonio J. , Levine Audrey D. , Nayak Bina S. , Harwood Valerie J. , Rhea Lisa R.
Published: December 2006

A common operational problem in leachate collection systems is clogging due to the formation of deposits within pore spaces and collection pipes. The role of co-disposal of municipal solid waste (MSW) and combustion residues from waste-to-energy (WTE) facilities in clogging is evaluated in this paper. Five parallel lysimeters were operated in monofill or co-disposal mode using MSW, WTE combustion residues, and water/wastewater treatment byproducts. Leachate was applied to each lysimeter to simulate sequential flooding and draining and leachates were characterized over a 7-month period. Waste composition and the presence/absence of biological activity influenced the redox potential, pH, and alkalinity, which impacted the rate and extent of biological degradation and chemical solubility. Calcium carbonate was identified as the most abundant chemical precipitate. Leachates from ash mono-fills were highly alkaline (pH > 11) and had higher ionic strength due to relatively higher levels of calcium and other minerals, while carbonate levels were limited due to the lack of biological activity. The MSW monofill generated leachates with high levels of biological activity, lower concentrations of calcium, and a rich carbonate system. Co-disposal of MSW, combustion and treatment process residues generated leachates that were not limited in either calcium or carbonate, creating ideal conditions for formation of precipitates.
High-spacing irregularly interstratified layer-silicates in the alluvial soil clays of Meerut, India
Authors: Tomar K. P.
Published: December 2006

The mineralogy of the fine clay fraction (<0·2 μm) of two soil pedons (Aquic and Udic Haplustalfs) representing the wheat-sugarcane belt of the Indo-Gangetic alluvial plain was studied by X-ray diffraction, differential thermal analysis, transmission electron microscopy, and by chemical analysis. The XRD patterns are characterized by unusually high spacings which are interpreted in terms of an interstratification comprising smectite, illite and ‘chlorite’ components. The CEC data (Ca/Mg and K/NH4) also indicate the possible presence of vermiculite. A plateau bridging the 7–10 Å maxima in K-saturated specimens heated at 300°C suggests interstratification of kaolinite and smectite, although this may not be part of the above interstratification. The diffuse bands shown by Mg-glycerol-solvated Ap-horizon clays at ∼21 Å, and the increasing elimination of XRD peaks in the > 10 Å region with distance from the surface, suggests that the expanding layers have a slight tendency to segregate in Ap horizon samples and that randomization tends to increase with depth. Discrete illite and small amounts of kaolinite were also detected.
Thermal stability of chlordimeform-montmorillonite complex
Authors: Hermosín M. C. , Cornejo J. , Pérez-Rodriguez J. L.
Published: December 2006

Studies of the thermal stability of organic compounds adsorbed on clay minerals are of interest from several points of view, e.g. the type and strength of bonding forces between the organics and the clay surfaces (Chou & McAtee, 1969; Yariv et al., 1971; Lacher et al., 1981), and the effect of the clay surface on stability or degradation mechanism of the organic compounds adsorbed on clays (Bodenheimer et al., 1966; Yariv et al., 1971; Durand et al., 1972).
An 57Fe Mossbauer effect study on glauconites from different locations in Belgium and Northern France
Authors: De Grave E. , Vandenbruwaene J. , Elewaut E.
Published: December 2006

Sixteen glauconite samples from different locations in Belgium and Northern France were investigated by 57Fe Mössbauer spectroscopy at room temperature. The spectra were fitted with three Fe3+ and two Fe2+ doublets, both Fe species occupying M1(trans) and M2(cis) sites in the T-O-T layers. The third Fe3+ doublet was assigned to interlayer ferric complexes. The observed Mössbauer parameters did not show significant variations from sample to sample. No direct relation between K and Fe content was observed, although within some distinct groups (e.g. Bande Noire, Cenomanian) the amount of Fe2+ increased with increasing K content.
Characterization of smectites synthesised from zeolites and mechanism of smectite synthesis
Authors: Komarneni S. , Breval E.
Published: December 2006

Smectites were synthesised hydrothermally from zeolites in an Mg-rich brine at 300°C under a confining pressure of 30 MPa and characterized by XRD using the Greene-Kelley Li-saturation test and the K+-saturation/glycolation test. The synthetic smectites were found to be dioctahedral with only tetrahedral negative layer charge; the layer charge was also deduced to be low and they are classified as beidellites. The mechanism of formation includes H+saturation of zeolites by the hydrolysis of Mg2+under hydrothermal conditions, followed by decomposition of the zeolites and recrystallization to beidellites. These results show that solution chemistry is an important factor affecting stability of zeolites under hydrothermal conditions.
Mineralogical evidence for sediment derivation and ice movement within the Wash drainage basin, eastern England
Authors: Wilmot R. D.
Published: December 2006

The Wash drainage basin contains four principal river systems. Samples were collected from the freshwater and estuarine reaches of each of these, and silt- and clay-grade fractions were separated and examined by XRD. The clay mineralogy of each of the rivers is different; in the north the Witham sediments contain chlorite, the Welland and Nene samples contain vermiculite, with a higher proportion of kaolinite in the former, while in the south the Ouse sediments contain smectite. The clay fractions of the samples from the estuarine reaches all contain chlorite, confirming that non-fluvial sources must contribute to the sediments of the Wash. Comparison of this pattern of clay mineralogy with that for the underlying Jurassic and Cretaceous rocks shows that there was relatively little modification during the Pleistocene glacial periods. Such a pattern supports recent work which suggests that ice moved through the Wash gap and then fanned out from the Fenland area, rather than entering the region from the north.
Vermiculites hydratees a une couche
Authors: De La Calle C. , Suquet H. , Pezerat H.
Published: December 2006

Resume

Les hydrates à une couche des vermiculites présentent cinq modes d'empilement. Aux cations de petit et de grand rayon ionique (Li et Ba) correspondent des modes d'empilement particuliers. Les cations (Na, Mg, Ca et Sr) conduisent chacun à deux modes d'empilement correspondant à deux stades différents d'hydratation.
Electron spin resonance studies of montmorillonites
Authors: Crăciun C. , Meghea Aurelia
Published: December 2006

Sixteen montmorillonites (8 normal and 8 abnormal using DTA dehydroxylation criteria) from the Gurasada bentonite deposits, Romania, were investigated by ESR. The spectra showed two features: ag= 4·3 signal attributed to isolated Fe3+ions and a broad resonance withg∼ 2·0 which was interpreted as arising from exchange interactions between clusters of Fe3+ions. Additional experiments suggested that the latter resonance could have a structural component. The line-shape of the two resonances varied between normal and abnormal montmorillonites, indicating that the distribution of the Fe3+ions between internal phase (montmorillonite lattice) and external phase (montmorillonite surface) was different for the two varieties.
Order-disorder in 1:1 type clay minerals by solid-state27Al and29Si magic-angle-spinning NMR spectroscopy
Authors: Komarneni S. , Fyfe C. A. , Kennedy G. J.
Published: December 2006

The applicability of27Al and29Si magic-angle-spinning nuclear magnetic resonance (MASNMR) spectroscopy to the investigation of order-disorder in 1 : 1 dioctahedral layer-silicates was tested.27Al and29Si MASNMR showed the existence of short-range order in all these systems while XRD showed different degrees of long-range order-disorder. Spectra obtained on kaolinite and metakaolin clearly showed the transformation of some octahedral Al in kaolinite to tetrahedral coordination in metakaolin and also showed short-range Al and Si disorder in the latter. This suggests that structural re-arrangement on thermal treatment can be monitored by this technique. These results further suggest that MASNMR can detect short-range order, which is complimentary to the information that XRD provides regarding long-range order.
Nickel-bearing clay minerals: I. Optical spectroscopic study of nickel crystal chemistry
Authors: Manceau A. , Calas G. , Decarreau A.
Published: December 2006

Nickel crystal chemistry was systematically studied in various phyllosilicates, mainly the natural phases selected from the ‘garnierites’ of the supergene ore deposits of New Caledonia. Minerals which do not usually occur in New Caledonian parageneses were synthesised, as they could represent intermediate phases of genetic importance. In the kerolite-pimelite series, a linear relationship occurred between the ratioI(13,20)/I(02,11)of thehkbands and Ni-content. Diffuse reflectance spectra were used to derive the crystal chemical parameters of Ni. These confirmed its divalent character and its occupation of octahedral sites; the resulting structural distortion was slight and could not be detected in some minerals. There was no optical evidence for Ni atoms in 4-fold coordination. The two main parameters which showed significant variations among the studied phases were site distortion and crystal field stabilization energy (CFSE). Site distortion was at a maximum in trioctahedral smectites and sepiolite. CFSE depended on the mineralogy, crystallinity and chemical composition (Al-content) of the phase. Finally, clay minerals are classified according to the increasing stability of Ni in the octahedral sheet, which has been tentatively related to the geochemical distribution of this element. Secondary minerals are usually enriched vs. primary ones and among them are nepouite and kerolite which exhibit a high CFSE in contrast to sepiolite.
Phyllosilicates and other layer-structured materials in stony meteorites
Authors: Barber D. J.
Published: December 2006

Current thinking regarding the possible origins and probable evolutionary histories of meteorites is summarized. Selected data concerning the composition, petrology and other characteristics of the CI and CM groups of stony meteorites in which layered minerals principally occur are then presented. Layered compounds, mainly phyllosilicates, are shown to form a major part of the fine-grained matrix of the CI and CM meteorites, which are classified as carbonaceous chondrites. The results of recent investigations of matrix mineralogy are reviewed, with particular emphasis on the findings of electron microscopy. Several forms of Fe-Mg-serpentine have been identified as the principal phyllosilicates. ‘Poorly-characterized phases’ in CM meteorites have proved to be tochilinite and intergrowths of tochilinite with serpentines. The results generally indicate that the phyllosilicates and most other matrix minerals formed by aqueous alteration in the regoliths of the CI and CM parent bodies; but there is isotopic evidence for the incorporation of components and possibly mineral grains which predate the solar nebula. It is concluded that more detailed chemical and mineralogical information about the phyllosilicates and associated minerals will enable useful constraints to be placed on the possible identities of their precursors and the environments in which both they and the matrix minerals formed.
Weathering in a marine clay during postglacial time
Authors: Pederstad K. , Jørgensen P.
Published: December 2006

Marine clays of SE Norway lifted above sea-level have been subjected to weathering for 8500 years. As a result of this weathering a major part of the quartz, K-feldspar and plagioclase disappeared in the 0·2–0·6 µm fraction. Trioctahedral illite passed through the sequence: illite → mixed-layer illite-vermiculite → vermiculite → dissolution. This transformation started at a depth of 3 m, and the 2:1 layers dissolved in the upper part of the profile. Chlorite was broken down by weathering into finer particles. As a result, chlorite was first removed from the coarser fractions. Dioctahedral illite in the clay fractions passed through the following transformations in the upper part of the profile: illite → mixed-layer illite-vermiculite → vermiculite → chloritized vermiculite. Weathering models for the size fractions 0·2–0·6 and 0·2–2 µm showed that total amounts of dissolved material from these fractions in the upper part of the profile could be calculated as 55 and 38%, respectively. Dioctahedral 2:1 layers were most resistant to weathering, resulting in 75% dioctahedral phyllosilicates in the 0·2–0·6 µm fraction in the uppermost part of the profile, in contrast to 30% dioctahedral illite in the unweathered sample. This study illustrates the importance of investigating different fractions and not only material finer than 2 µm.
The physical dimensions of fundamental clay particles
Authors: Nadeau P. H.
Published: December 2006

The thickness, length, width, area and perimeter of 575 particles from 16 aqueously dispersed samples of a variety of interstratified clays, smectites and illite have been recorded using TEM techniques. Complete dispersion of the clay material was achieved by saturating the clay with either Na+or Li+, removal of excess ions by dialysis, and isolation of the <0·1 or <0·2µm fraction by centrifugation. The samples have mean maximum dimensions of 1900 to 90 nm and the dispersed system can be considered as colloidal in nature. The mean thickness of the clays is about 1 nm for smectites, corresponding to that of elementary 2:1 silicate layers, from 1·9 to 4·9 nm for the interstratified clays, and 9 nm for illite. From these data the volume, total surface area and other parameters have been calculated and compared with independent determinations of surface area and CEC. The total surface area by TEM, assuming a density of 2·6 g/cm3, varies from ∼675 m2/g for smectites to 86 m2/g for illite, and is inversely proportional to the mean particle thickness. The charge density of monovalent cation exchange sites on the surface of the particles as determined for nine of the samples varies from 0·54 to 1·16 nm2/site. The particle-thickness distribution data can be used to calculate interstratified XRD layer-sequence probabilities and composition parameters, and agree with XRD data for interstratified clay with <60% illite layers. The thickness data also provide a rationale for the interpretation of TEM lattice-fringe images. Relationships between the particle area, length, thickness and volume are shown to be potentially useful in assessing the mechanism(s) of crystal growth of these extremely small phyllosilicate particles.
Evaluation of selective dissolution extractants in soil chemistry and mineralogy by differential X-ray diffraction
Authors: Campbell A. S. , Schwertmann U.
Published: December 2006

Selective dissolution analysis is widely used to separate various soil minerals (e.g. oxides and oxyhydroxides of Al and Fe, allophanes, phyllosilicates) from each other. Although a wide variety of reagents has been used for some of these determinations, few rigorous comparative studies have been attempted. Too often, reagents used to extract particular soil components are evaluated using geological or other specimens that may bear little resemblance to soil minerals formed by pedogenic processes; the investigations of Borggaard (1982) and Chao & Zhou (1983) are two recent examples of such an approach. Insufficient use has been made of difference infrared spectra (Wada & Greenland, 1970) obtained from soil samples.
Synthesis of Sepiolite at Room Temperature from SiO2and MgCl2Solution
Authors: Abtahi A.
Published: December 2006

The occurrence of sepiolite and palygorskite in soils, Eocene limestones and the Asmari dolomitic limestone of Iran has been described by many workers (Bentoret al., 1963; Martin Vivaldi & Robertson, 1971; Abtahi, 1977, 1980). No studies have been carried out on the genesis of these minerals in Iranian soils, however, and the purpose of this note is to describe some experimental conditions under Which sepiolite can form, and which also could apply to the genesis of the mineral in Iranian soils.
On the occurrence of Phenacite in Cornwall
Authors: Russell Arthur
Published: December 2006

The mineral phenacite (beryllium ortho-silicate) has not previously been recorded from the British Isles. The following notes contain an account of its characters and mode of occurrence at five distinct localities in Cornwall. The occurrences are described in the order of their discovery.

During the early part of 1905, while examining the Cheesewring Quarry, in company with Mr. F. H. Butler, who on a previous visit had discovered bertrandite at this locality, I paid special attention to the diseovcry, if possible, of any other beryllium minerals. I was fortunate enough, after much searching, to find a specimen showing three small crystals that at once suggested the mineral phenacite ; a surmise which On examination proved correct.
On the crystalline form of nitrogen sulphide
Authors: Herbert Smith G. F.
Published: December 2006

In the course of an investigation of the atomic weight of nitrogen Mr. F. P. Burt, of University College, London, prepared by the following process crystals of nitrogen sulphide, N4S4, surpassing in purity any that had been previously obtained. The nitrogen sulphide was recrystallized from benzene, washed with carbon disulphide to remove as much sulphur as possible, and finally washed with a little cold benzene. The product was powdered on a porous tile, and kept in a desiccator with calcium chloride and cocoa-nut charcoal until it no longer smelt of benzene. It was then sublimed in vacuo over silver gauze heated to 100° C. in a steam-jacket, by which means the absence of liquid or gaseous inclusions and of free sulphur in the sublimate was assured.
A universal goniometer
Authors: Hutchinson A.
Published: December 2006

The instrument to be described in the following pages is a goniometer of the suspended type. It is intended primarily for tlle examination of small crystals, and by its aid all the usual crystallographic and optical determinations can be readily carried out. In its design the attempt has been made to combine efficiency with simplicity and strength of construction, together with adaptability to very various purposes. The instrument was completed in the spring of 1899, and has been in continuous use in the Mineralogical Laboratory at Cambridge ever since. Other instruments of the same general type were in existence at the time, or have been described during the past twelve years, and several features which were novelties when it was first constructed can no longer lay claim to originality.
Notes on Cassiterite in the Malay Peninsula
Authors: Scrivenor J. B.
Published: December 2006

The following notes on some peculiar forms of cassiterite found in the Malay Peninsula will, it is hoped, prove of interest and an addition to our knowledge of the mineral.

It is now well known that the most effective method of separating wolframite from eassiterite on a commercial scale is the electromagnetic process, which, in theory, lifts all the wolframite from the ore and lèaves a concentrate of cassiterite. In practice, however, the separation is rarely, if ever, perfect; and it has been possible for the writer to obtain some interesting information bearing on the point, the most valuable being the discovery of a few specimens of cassiterite that may be termed magnetic in that it can be lifted by an electromagnet.
Prehnite from the Lizard district, Cornwall
Authors: Russell Arthur
Published: December 2006

Hitherto the mineral prehnite has been recorded from one locality only in Cornwall, namely, in the cliffs between Wheal Cock and the Crowns Rock, Botallack, St. Just. It occurs there as pale-green, globular aggregates composed of indistinct, curved crystals, and forms veins traversing a narrow strip of greeustone which has intruded itself through the granite mass; associated minerals are stilbite and axinite.

In the summer of 1910 the writer collected several crystallized specimens of this mineral at Pare Bean Cove, Mullion, the locality from which Dr. J.S. Flett and Mr. W. F. P. McLintock obtained the fine crystallized specimens of datolite, recently described by the latter. The prehnite occurs here in two distinct and somewhat unusual types of crystals—tabular and prismatic.
On Strüverite from the Federated Malay States
Authors: Crook T. , Johnstone S. J.
Published: December 2006

The mineral dealt with in this paper was sent for examination the Imperial Institute by Mr. J. B. Scrivener, Government Geologist to the Federated Malay States. It occurs on the river Sebantun, about half a mile above Salak North village, Kuala Kangsar district, Perak. The ground on which it was obtained was held on a tin-mining lease, but had to be abandoned owing to the presence of the unknown mineral, which rendered mining unprofitable.
A simple graphic method for determining extinction-angles in sections of biaxial crystals
Authors: Smith H. G.
Published: December 2006

The relationship between the optic axes and the vibration-directions in a section of a biaxial crystal was enunciated by Biot in 1819, and may be stated as follows : The vibration-directions in any section of a biaxial crystal are given by the bisectors of the angles between the optic axes as projected on the plane of section.

Dr. Fletcher and Mr. Harker have elaborated the idea, but there appears to be room for a simpler presentment, more adapted to the needs of students, which does not involve the use of the optical indicatrix or the spherical projection.
On the identity of Neocolemanite with Colemanite
Authors: Hutchinson A.
Published: December 2006

The beautiful crystals of colemanite from the Death Valley, Inyo County, and from the Calico district, San Bernardino County, California, were described almost simulfmneously in the autumn of 1884 by several different observers, The most complete examination we owe to Jackson, who identified forty-forms and determined the axial ratios which are usually accepted for the mineral, namely, a : b : c = 0.774843 : 1 : 0.540998 : β = 110° 9′ 15′′. Very similar values for these constants were adopted by Hiortdahl and by vom Rath.
On the temperature of optical uniaxiality in Gypsum
Authors: Hutchinson A. , Tutton A. E. H.
Published: December 2006

In the account of an investigation of the optical properties of gypsum published by one of us (A. E. H. T.) in 1908 it was stated, as the result of direct measurement in sodium-light of the optic axial angle of a section-plate perpendicular to the first median line, which was heated in an air-bath, that the substance became uniaxial at 105.2° C. Three other section-plates examined subsequently gave somewhat higher values, the results ranging from 109.5° to 114.2° C. These figures were arrived at after a considerable correction, amounting to as much as 7°, had been applied for conduction along the crystal-holder, the temperatures actually observed being greater by this amount.
Description of large crystals of Seligmannite and Dufrenoysite
Authors: Solly R. H.
Published: December 2006

In the summer of 1906 some large crystals of seligmannite were found in an irregular, elongated cavity in the dolomite-rock of the Lengenbach quarry at Binn, Switzerland. Owing to their brittle nature many of them were broken when the rock was blasted, but I was in the quarry at the time and collected all the fragments. The largest crystal broke after it had been measured, and Dr. G. T. Prior's analysis II was made on portions of it, his other analysis, I, being made on measured crystal fragments found with the large crystal. The streak of the present crystals is black and inclined to purplish in colour, while that of the crystals first described by me was chocolate-coloured.
Hatchite, a new (anorthic) mineral from the Binnenthal
Authors: Solly R. H. , Herbert Smith G. F.
Published: December 2006

Nearly ten years ago, in 1902, five small crystals were noticed by one of us on a crystal of a sulpharsenite of lead, probably rathite, which had been found in the Lengenbach quarry that summer. Although from their lead-grey colour they also appeared to belong to a sulpharsenite of lead, in habit and appearance they were unlike the crystals of any such species as yet known. The crystals were measured, and were shown at the anniversary meeting, of the Society, November 18, 1902, but the measurements were not published at the time in the expectation that further material would afterwards be found which would enable an analysis to be made and perhaps throw fresh light on the morphological characters of the crystals.
On varieties of Zirkelite from Ceylon
Authors: Blake G. S.
Published: December 2006

This paper deals with various specimens received at the Imperial Institute from Ceylon. Some of these specimens were obtained by Dr. A. K. Coomaraswamy at Wa]aweduwa, in the Bambarabotuwa district of the Sabaragamuwa province, during the course of the Ceylon Mineral Survey. Walaweduwa is a little to the north of the Bambarabotuwa locality where thorianite has been found in conslderable abundance. Dr. Coomaraswamy also found specimens in the upper part of the Alupola oya, a stream in the same district. A chemical examination of these specimens showed that titanium dioxide, zireonia, thoria, lime, and iron oxide were the chief constituents.
Note on the determination of the optic axial angle of a crystal in thin-section by the Mallard-Becke method
Authors: Collingridge Harvey
Published: December 2006

Mallard's original method was based on the measurement of the linear distance, as determined by an eyepiece-micrometer, between the optic axes in a section of the crystal at right angles to the acute biseetrix viewed in convergent light.

Professor F. Becke implored on this method by utilizing sections which were not at right angles to the acute hissetrix, but in which both optic axes were visible in the field. He projected both axes by means of an Abbe camera lucida on to a revolving drawing-table, and by means of the Mallard equation plotted the axes on a stereographic projection and thus obtained the optic axial angle, the angles of course being corrected for refraction to the true angles in the crystal section. Professor Becke subsequently, by utilizing the Biot-Fresnel law, formulated a graphic method of obtaining the optic axial angle from a section in which only one axis was visible.
An account of the minerals found in the Virtuous Lady Mine, near Tavistock
Authors: Russell Arthur
Published: December 2006

Virtuous Lady Mine is situated in the parish of Buckland Monachorum on the right bank of the river Tavy close to its junction with the river Walkham, at a distance of three miles south of Tavistock in Devonshire. The mine has long been famous for the charm of its situation, and in addition possesses for the mineralogist an especial interest owing to the peculiar beauty and unusual character of the mineral specimens it has yielded. The early history of the mine is lost in obscurity, as also is the origin of its curious name, which, however, local tradition ascribes to Queen Elizabeth.
The Meteoric Stones of Baroti, Punjab, India, and Wittekrantz, South Africa
Authors: Prior G. T.
Published: December 2006

In 1912 Mr. N. B. Kinnear, Curator of the Bombay Natural History Society's Museum, brought to me at the British Museum, for identification, a specimen of a supposed meteorite which had been sent to the Bombay Natural History Society by the late General W. Osborn.

General Osborn stated that, in November, 1910, on arrival at his usual winter quarters in the hill station of Kotheir in the Punjab, he visited his friend, the Rajah of Bilaspur, who presented him with a fragment, weighing about a quarter of a pound, of a meteorite which had fallen in daylight at the village of Baroti, in the Bilaspur (Simla) district, one day during the month of September, 1910.
The genetic classification of rocks and ore deposits
Authors: Crook T.
Published: December 2006

During the last decade there has been no lack of controversy on the subject of rock classification, but the dispute has concerned igneous rocks almost entirely. Petrography has been threatened by an effort to reduce it to an independent science of igneous rocks, and in consequence of this there has been a tendency to neglect its wider aspects. Important as igneous rocks are, their formation is less well understood than is that of some other sub-groups of rocks ; moreover, they constitute one only of some six or seven sub-groups, and it is the business of petrography as a science to deal with these rocks as a whole. The student of petrography should be encouraged to take this wider view. He shonld look at these different sub-groups of rocks in their proper geological perspective, and approach the study of the classification of igneous rocks with a knowledge of the principles that are applicable to the classification of rocks as a whole.

The discussion concerning the classification of ore deposits has proceeded on independent lines, and in a more well-balanced manner than has that of rocks. With ore deposits, as with rocks generally, genetic principles have triumphed; but the application of these principles to rocks long preceded their application to ore deposits. Iu recent years it has become apparent that the fundamental requirements for the classification of rocks and ore deposits are essentially the same ; and in view of the identity of their interests, both subjects are treated in this paper.

The aims of this paper are : To define the basis of genetic classification ; to give a brief historical account of classification on genetic-geological principles ; to point out defects in the present system of arrangement ; and to suggest an altemmtive scheme of grouping that is in closer accord with geological and genetic principles.
Litharge from Zarshuran, Persia
Authors: Scott Alexander
Published: December 2006

The specimen to which this paper refers, is one of a number of minerals from Kurdistan, presented to the Hunterian Museum, in Glasgow University, by Mr. D. Ferguson, to whom I am indebted for the following particulars of the occurrence. The exact locality is the Zarshuran River, in Kurdistan, where a large mineral vein, which has been worked for centuries for orpiment, is found. The country-rock is red sandstone, overlying, unconformably, altered slates and schists, which are intruded by a boss of felspathic granite or syenite. Near the surface the vein-stone is chiefly a kind of calc-sinter, but this disappears as the depth increases and calcite becomes the predominant mineral in the gangue, being associated with some quartz and fluorspar.
A new locality for Voelckerite and the validity of Voelckerite as a mineral species
Authors: Rogers Austin F.
Published: December 2006

In 1912 the writer proposed the name voelckerite (in honour of Dr. John Augustus Voelcker, the well-known English agricultural chemist, who made important contributions to our knowledge of the~ chemistry of apatlte) for the basic calcium phosphate, 3Ca2(PO4)2.CaO , related to apatite. The fact that apatite is often deficient in fluorine and chlorine was proved by Voelcker and by Hoskyns-Abrahall, both of whom gave as the general formula of apatite 3Cas(PO4)2.Ca(F2,C]2,O ) or its equivalent Ca10(PO4)6(F2,Cl2,O ). Carnot also noted the deficiency of chlorine and fluorine in apatite from Tyrol, but he offered no explanation.
Note on the colour and alteration of Pyrrhotite
Authors: Mennell F. P.
Published: December 2006

The colour of the well-known iron sulphide, pyrrhotite or pyrrhotine, is given in most treatises on mineralogy as 'bronze-yellow'. Dana calls it ' between bronze-yellow and copper-red ', and also notes that it is 'subject to speedy tarnish'. The accuracy of the last statement will not be doubted by any one who has had much acquaintance with mining operations in districts where pyrrhotite is a common lode mineral, but it does not appear to have been put on record in any scientific publication that the characteristic colour, not very accurately designated 'bronze-yellow', does not seem to be the original one of the unaltered mineral.
The Garnets and streaky rocks of the English Lake District
Authors: Green J. Frederick N.
Published: December 2006

There exists in the Lake District a peculiar type of metamorphism of which no analogue has, as far as the writer is aware, been described elsewhere, with the exception, perhaps, of South America. It is indicated chiefly by the presence of garnets and 'streaks ', the former being found indifferently in every variety of igneous rock of the district, the latter being mainly confined to the rhyolites or quartzkeratophyres. The most similar known to the writer is at Oyacachi in Ecuador, whence veto Rath has described flow-brecciated soda-rhyolites which sometimes contain red garnets. He also refers to rocks which may be 'streaky'.
On Bassetite and Uranospathite, new species hitherto classed as Autunite
Authors: Hallimond A. F.
Published: December 2006

The name autunite was originally g!ven to the well-known mineral from Autun, but it would seem that no crystals of this material have been found that would afford measurements oi1 the goniometer. As the result of optical examination Des Cloizeaux (2) concluded that the mineral was biaxial, and he observed further that the angle decreased when the specimen was heated (6); the extinction was apparently straight, and he therefore referred the trysts,Is to the rhombic system ; with the contact goniometer he found mm'=90°48'.
The dispersion phenomena and the influence of temperature on the optic axial angle of Sanidine from the Eifel
Authors: Kôzu K.
Published: December 2006

In the course of my study of the dispersion phenomena of the felspar group in the Mineralogical Laboratory of the University of Cambridge, Professor Lewis advised me to study the remarkable properties of sanidine from the Eifel, which were first noticed by Des Cloizeaux, and he very kindly placed the mineral sections in the Museum at my disposal. In order to be certain of the material used, application was made to Professor A. Lacroix of Paris, who with the courtesy and generosity characteristic of his countrymen was good enough to send some fragments of the very crystals used by Des Cloizeanx in his classical researches.
Chabazite and assodated minerals from County Antrim
Authors: Herbert Smith G. F.
Published: December 2006

Eight years ago (in 1907) Mr. F. N. Ashcroft, who for many years has devoted much of his leisure to bringing together choice specimens of the species included in the zeolitic group of minerals, turned his attention to the specimens occurring in the cavities of the basalt of Co. Antrim. He was fortunate enough to secure the services of Mr. Robert Bell, of Belfast, ill his quest, and between them they have searched many of the quarries and other places likely to yield good specimens of these minerals. Some of the early specimens obtained through Mr. Bell, which, however, did not include any chabazite, were exhibited by Mr. Ashcroft at the anniversary meeting of the Society, on November 12, 1907.
Proustite from Cobalt, Ontario
Authors: Parsons Arthur L.
Published: December 2006

During the summer of 1913 the Royal Ontario Museum of Mineralogy secured a nmnber of samples of ruby-silver from the collection of a deceased mining engineer who had been employed in the Cobalt district. Judging from their association it is presumed that they were obtained from the O'Brien mine. The crystals for the most part are less than two millimeters in length and very few exceed a millimeter in diameter. They are light ruby-red in colour and exceedingly brilliant, and casual inspection suggested that they were proustite. As this mineral had not been described from the Cobalt region, it seemed desirable to confirm this supposition by chemical analysis and crystallographic measurement.
On a series of volcanic rocks from the neighbourhood of the Lucalla River, Angola
Authors: Holmes Arthur
Published: December 2006

Last year, while working through the geographical collection of rocks in the Geological Department of the Imperial College, I found an interesting series of volcanic rocks from the neighbourhood of the Lucalla River in the district of Cambambe, Angola, which hitherto has not been described. The specimens were collected about the year 1860 by J. J. Monteiro, a former student of the Royal School of Mines, who devoted many years to the exploration of Angola. The collection, though consisting of only ten specimens z comprises porphyritic basalts, alkalitrachytes, a nephelinite allied to monchiquite, and an augite-andesite.
The numerical relation between the zones and faces of a polyhedron
Authors: Fedorov E. S.
Published: December 2006

In Professor G. Cesàro's note 'Sur une propriété numérique de l'ensemble des axes de symétrie situés dans los plans de symétrie d'un polyèdre' is given the formula ((1) on p. 174)
On the mesosiderite-grahamite group of Meteorites : with analyses of Vaca Muerta, Hainholz, Simondium, and Powder Mill Creek
Authors: Prior G. T.
Published: December 2006

In the Rose-Tschermak-Brezina classification of meteorites the intermediate class of stony-irons, in which iron and stony matter occur in approximately equal amounts and to which Maskelyne gave the name siderolites, is divided into (1) siderolites proper, including the groups of the pallasites and the siderophyres, and (2) lithosiderites, comprising the groups of tile mesosiderites, glahamites, and ]odranites. Mesosiderites are defined as consisting of iron and crystalline olivine and bronzite, and grahamites of the same constituents with the addition of plagioclasefelspar.
A method for the quick determination of the approximate amount and composition of the nickeliferous iron in Meteorites ; and its application to seventeen meteoric stones
Authors: Prior G. T.
Published: December 2006

In the classification proposed by the author in a previous paper meteorites are divided into five groups according to the ratio of iron to nickel in the nickeliferous iron they contain. In the case of the meteoric irons such a classification, as shown by Farrington's list of analyses, is a natural one, since the structure of the irons, as revealed by etching, varies with the amount of nickel they contain. Thus Group 1, in which the metal is poor ill nickel, with a ratio of Fe to Ni of 13 upwards, includes nickel-poor ataxites, hexahedrites, and Coarsest and coarse octahedrites ; Group 2, in which Fe : Ni =8-13, the rest of the octahedrites from medium to finest ; Group 8, in which Fe : Ni = 5-8, nickel-rich ataxites; Group 4, in which Fe: Ni = 2-5, ataxites still richer in nickel; while Group 5 may include the doubtful Oktibbeha meteorite in which the ratio of iron to nickel is even less than one.
A Students' Goniometer
Authors: Herbert Smith G. F.
Published: December 2006

This form of goniometer was designed in order to provide for the use of students of elementary crystallography, at as moderate a cost as possible, an efficient instrument for the measurement of the interracial angles of crystals. It is of the customary type, in which the direction of reference is given by the reflection of a distant object in a small plane mirror without optical aid, and the axis of the grHduated circle is horizontal. The mirror measures about 45 by 25 ram. and its frame is rigidly attached to the ball of a ball and socket joint, so that it is adjustable in any direction; the socket is split, and a screw linking the halves enables it to grip the ball firmly.
New crystal-forms on Pyrites, Calcite, and Epidote
Authors: Spencer L. J.
Published: December 2006

The dyakis-dodecahedron (641) was observed on certain of the Museum specimens by Mr. Richard Elliot Steel in 1879 and again by myself in 1894; and although several memoirs on the crystallography of pyrites have been published since those dates, this form has not hitherto been recorded for the mineral.

Under the register-number 31679 are a number of small specimens and isolated crystals of pyrites, on three of which the form in question is deve]opod. These were purchased in 1860, and their locality is unknown. They show some matrix of black shale, and, unfortunately, are gradually being broken up by decomposition.
The fibrous Gypsum of Nottinghamshire
Authors: Alfred Richardson W.
Published: December 2006

The Upper Triassic sediments are assumed to have contained concentrated solutions, which caused, or contributed to, their dehydration and contraction. The contraction of a colloidal mass results in the production of tension planes, and unless compensated by settlement, rupture finally ensues. Relief of pressure by rupture may bring the sohtions into the labile state, when innumerable closely-spaced centres of crystallization will be set up. The crystals, fed by vertically diffusing solutions, grow vertically, so long as contraction and feeding continue. When, at length, contraction attains its limit, further growth is resisted, and the stresses set up, transmitted to the central parting, produce bending and other pressure effects in the veins.
On the determination the optic axes of a crystal from extinction-angles
Authors: Hilton Harold
Published: December 2006

Various authors have discussed the problem how to determine the position of the optic axes of a biaxial crystal when the extinction-angles on n different faces have been observed. It has been proved that a unique solution is possible when n = 1, 2, or 4, according as the crystal is orthorhombic, monoclinic, or triclinic. It is assumed (and will be assumed in this paper) that the n faces have general positious. The result is uot true, if one or more of the faces has a specialized position. For instance, the extinction-angle ou a face of an orthorhombic crystal which is parallel to an axis of symmetry will obviously not suffice to determine the position of the optic axes.
An example of porphyry-quartz, from the Esterel Mtns., France, twinned on face (1012)
Authors: Drugman Julien
Published: December 2006

It is now well recognized that quartz undergoes a sudden change near 575° C., and Wright and Larsen (1) have shown that the characteristics of quartz formed above or below this point are so marked that they can be utilized to determine the temperature of formation of rocks containing quartz. Quartz formed above 575° so-called β-quartz, is of distinctly hexagonal development, and occurs generally as regular hexagonal bipyramids with or without a subordinate prism-face. These external characteristics are of course preserved on cooling, and the bipyramids are converted into apseudomorphous aggregate of α-quartz.
On the structure and composition of the Strathmore meteorite
Authors: McLintock W. F. P. , Ennos F. R.
Published: December 2006

The fall of this meteorite, which took place at 1.15 p.m. on December 8, 1917, was witnessed by many people over a large area. The circumstances were investigated immediately by Mr. Henry Coates who has given in a paper already published full and accurate details of the appearance of the meteorite as it described its path, the direction in which it travelled, and the noise caused by its explosion. Fragments were recovered at four different localities lying on a line running from South Corston in Forfarshire north-westwards for about six miles to Easter Essendy in Perthshire, and the following table gives the particulars of the weights and localities of the various pieces.
On Glauconite from the Greensand near Lewes, Sussex; the constitution of Glauconite
Authors: Hallimond A. F.
Published: December 2006

A Boring male at Iford Manor, 1½ miles S.E. of Lewes, Sussex, yieled the following section:

The lower sand contained numerous grains of glauconite, while the upper bed was black when wet and consisted almost entirely of dark-green glauconite, with a few shell fragments and large quartz grains. The glauconite grains were small and were separated in an almost pure state by sieving; the portion coarser than 76 [wires to the inch] mesh contained the shell fragments, &c., while that below was nearly all glauconite, with a few very small grains of magnetite present in the sand.
The frequency-distribution of igneous rocks. Part II. The laws of distribution in relation to petrogenic theories
Authors: Alfred Richardson W.
Published: December 2006

In Part I of this paper the actual frequency-distribution of igneous rocks as revealed by the latest edition of Washington's collection of analyses was examined, and compared with that of earlier records. An attempt wilt now be made to determine the law of this distribution–a necessary preliminary to any petrogenic application of the results. The silica frequency will be considered since this has been found to give a curve more characteristic of igneous rocks than does any other oxide Now Dr. Harker pointed out that the silica distribution of records published in 1903 did not obey any simple law such as that of the probability curve, and the same conclusion applies to the collection of 1917. However, when the empirical method of Karl Pearson was applied to analyse the curve into component curves of error, fairly simple conclusions resulted.