bluuebunny/crossref_metadata_2025_split huggingface dataset:
An occurrence of grunerite at Pierrefitte, Hautes-Pyrénées, France
Authors: Warren Harry V. 
Published: December 2006

As grunerite is a somewhat uncommon mineral, and as its occurrence at Pierrefitte in association with lead and zinc ore is unusual, if not unique, it may be worth while to put on record the following notes on some material which I collected during an examination of the Pierrefitte deposits.The name 'grunerite' was originally given to a fibrous mineral approximating in composition to FeSiO3 and occurring with magnetite and garnet at Collobrières in the dept. of Var, in the south of France, which was described by Gruner in 1847. It was originally supposed to be a pyroxene, but was later shown by Des Cloizeaux and Lacroix to belong to the amphibole group. A similar mineral occurs in the iron deposits of the Lake Superior district, and elsewhere ; but it has not been recorded from the Pyrenees.
A chemical, optical, and X-ray study of nepheline and Kaliophilite
Authors: Bannister F. A. , Hey M. H. 
Published: December 2006

SummaryCorrelated data prove the approximate constancy of the number of oxygen atoms in the unit cells of several nepheline and elaeolite specimens. Thence the number of atoms of each kind per unit cell have been counted. The cell-volumes and optical properties have slso been correlated with the chemical composition. An approximate structure is suggested which, together with the chemical work, explains the variable composition of nepheline. The contents of the unit cell may be written Si16−nAln(Na,K,½Ca)nwhere n ranges from 6.6 to 8.2. Kaliophilite is shown to possess a much larger cell than that of nepheline, and its Lauegram exhibits higher symmetry. 'Pseudonepheline' (rich in potassium) has a slightly greater cell-volume than normal nepheline, but its Lauegram is almost identical and its axial ratio only slightly less.
The rôle of kyanite in the ' hornfels zone' of the Carn Chuinneag granite (Ross-shire)
Authors: Tilley C. E. 
Published: December 2006

The metamorphism surrounding the granite of Carn Chuinneag in eastern Ross-shire provides the classical example of polymetamorphism in which a regional metamorphism is superimposed on a normal thermal metamorphism.Prior to the regional alteration a pelitic facies of the Moine sediments suffered metamorphism of a purely thermal type in the vicinity of the granite. At a subsequent date the whole region was involved in fold movements with the production of crystalline schists. In this deformation the belt of rocks surrounding the granite yielded in such a way that belts of the hornfels zone moved en masse and are preserved amidst rocks which are now typical crystalline schists, and all stages of transition between genuine hornfelses and typical micaschists can be traced in the field.
Some data on the iron-rich hypersthenes
Authors: Henry N. F. M. 
Published: December 2006

The first iron-rich hypersthene reported was from Vittinki in Finland and was described by M. Saxén in 1925. In 1932 N. Sundius showed that the so-called 'iron-anthophyllite' from Tunaberg in Sweden was really a very iron-rich hypersthene. He suggested that two other 'iron-anthophyllites' occurring similarly in the eulysites of Sweden at Bygdsiljum and at Mansjö might also prove to be really iron-rich hypersthenes.Here chemical and optical data are given for the Mansjö mineral which fits well into the series and proves to be slightly richer in iron than the Tunaberg one. Data are also given for hypersthenes from Loch Duich and from Glen Buchat in Aberdeenshire, while, thanks to the kindness of Professor P. Eskola, it has been possible to obtain a sample of the Vittinki mineral and to complete the data of M. Saxén.
Anomalies in the analytical determination of water in epidote
Authors: Smethurst A. F. 
Published: December 2006

Numerous veins and veinlets of epidosite traverse the crystalline schists and associated igneous rocks of the Malvern complex. They art fine-grained, compact rocks, of uniform texture and pale greenish-yellow colour, and vary in composition from almost pure epidote to mixtures of epidote with small quantities of quartz, sphene, sericitic mica, apatite, and, in almost insignificant amount, albite.Analytical investigation of these rocks revealed the fact that the epidote they contain holds its water more tenaciously than has hitherto been suspected : the determination of water-content by the methods usually applied to the analysis of rocks and minerals gave results which were so seriously low as to suggest that the mineral was essentially anhydrous. Though more drastic methods increased the yield considerably, they failed to liberate more than about 75 % of the amount of water which, theoretically, should be present.
Variability of garnet in granites
Authors: Brammall A. , Bracewell S. 
Published: December 2006

IN extending earlier work on the distribution and significance of manganiferous garnet in the Dartmoor granites, the senior author found it necessary to determine whether the average composition of the Dartmoor species was fairly represented by the single complete analysis (II, below) hitherto available - that of an aggregate of garnet fragments separated from crushed tor-granite.As a preliminary step a similar aggregate from the cordierite-rich granite exposed in the Sweltor quarry was analysed (I).
Biographical notices of mineralogists recently deceased. (Sixth series.)
Authors: Spencer L. J. 
Published: December 2006

In the following list of 36 lives, with a range in ages frdm 56 to 89, the average age is 71.0 years. The average of 460 lives noticed in this Magazine since 1877 is 65.9 years ; and in the six numbers of this series since 1919 there has been a gradual and steady increase from 63.6 to 71.0.Particulars respecting Czech, Italian, Japanese, and Russian subjects have been kindly supplied by Professors F. Slavlk, G. R. Levi, R. Ōhashi, and Mr. S. I. Tomkeieff respectively, and to these colleagues I express my thanks.
Eulysites and related rock types from Loch Duich, Ross-shire
Authors: Tilley C. E. 
Published: December 2006

Our knowledge of the rare rock type eulysite (A. J. Erdmann, 1846) comes almost wholly from Swedish occurrences amt hitherto no examples have been recognized from Britain. It is therefore of interest to place on record a new Occurrence of eulysites and related rocks from among Lewisian rocks of the Glenelg area, Scotland.The rocks shortly to be described come from the vicinity of Totaig on Loch Duich between Totaig and Letterfearn, little more than half a mile from the first described occurrence of eclogite in Britain. These eulysitic rocks crop out on the hillside immediately south-west of Druideig Lodge. About 200 yards south-west of the lodge coarse garnet-paragneisses form outcrops associated with grunerite- and cummingtonite-garnet-gneisses, and a similar interbanded association is found at higher levels.
The deuteric mineral sequence in the Enoggera granite, Queensland
Authors: Whitehouse Marjorie J. 
Published: December 2006

The Enoggera 'granite', in which occur the minerals to be described, is situated a few miles to the west of the city of Brisbane, and within the Greater Brisbane area. Deuteric and allied minerals have previously been recorded from quarries in the granite by H. C. Richards and W. H. Bryan, and a specimen is recorded ill the Queensland Mineral Index as 'Heulandite occurring as geodes in granite. Loc. Enoggera.'The granite itself is very varied in character, and Bryan has recognized two main types, a pink phase and a grey phase. The pink phase approaches an adamellite, while the grey is more granodioritic in character. There is, however, every gradation from one type to the other due to admixture, and this reaches its maximum in a hybrid rock formed presumably by the mingling of the two magmas.
Wollastonite solid solutions from Scawt Hill, Co. Antrim
Authors: Tilley C. E. 
Published: December 2006

Wollastonite at Scawt Hill, Co. Antrim, ocours as a constituent of both the exogeneous and endogeneous contactzones of the dolerite. In the former it is associated only with flint nodules in the metamorphosed chalk, in the latter, however, commonly as a minor constituent of certain of the hybrid types.In my original account a wollastonite-bearing augite-dolerite from this latter zone was figured without further description in the text (plate xvII, fig. 3). In examining the optical characters of wollastonites associated with hedenbergite, I had occasion to turn again to the wollastonites of this particular rock type.As indicated in the explanation of the figured section (loc. cir., p. 467), the dolerite is built essentially of sharply zoned brown titanaugite, labradorite, wollastonite, iron-ores, interstitial thomsonite, analcime, and accessory sphene. In this aggregate wollastonite forms subidiomorphic crystals averaging 1 ram. in size, and from a series of sections its predominant forms can be readily made out.
On the nature of withamite from Glen Coe, Scotland (With Plate IV.)
Authors: Osborne Hutton C. 
Published: December 2006

In 1824 Henry Witham discovered a beautiful red epidote mineral in the lavas of Glen Coe, Argllshire, which was described by Brewster under the name withamite. An analysis was made by Coverdale of obviously highly impure material, but later a more complete one was carried out by Heddle on carefully hand-picked mineral. Heddle admits, however, that his analysis shows ‘by no means a satisfactory agreement with the composition of epidote’, and from his figures it would seem very likely that his analysed material was also impure. In the Glen Coe Geological Survey Memoir no further data were recorded of this mineral, Heddle's analysis and description merely being quoted.The writer visited Glen Coe and collected material in a cutting on the new road, approximately 5½ miles west of King's House (Geological Survey, sheet 53), where it is fairly well exposed. It occurs in a fine-grained, rather altered andesitic rock, as narrow veinlets up to 120 mm. in length and 50 mm. in width ; also as infillings of vesicles. The veinlets may be straight or highly irregular; in the former case they possibly follow joint-planes, for the rock will often fracture along such a plane, producing one or two surfaces covered with the red epidote mineral. The vesicles vary greatly in size from approximately 0·3 to 70 mm., and in the larger ones calcite is a common associate.
A chemical and optical study of a low-grade metamorphic actinolitic amphibole from Coronet Peak, western Otago, New Zealand
Authors: Hutton C. Osborne 
Published: December 2006

This amphibole is an important constituent of an albite-epidote-actinolite-chlorite-calcite-schist from the summit of Coronet Peak in the Wakatipu district, western Otago. The mineral is somewhat concentrated into folia and porphyroblastie crystals up to 5·0 mm. in length, and is markedly flattened parallel to the orthopinakoid so that sections cut parallel to the schistosity exhibit numerous porphyroblasts, deeply coloured, poorly birefringent, and showing rather poor cleavage lines (fig. 1 A and B; fig. 2 A). In slices cut across the foliation numerous elongated end-sections are to be seen with development of small orthopinakoids (fig. 2 B).The refractive indices (±0·002) are α 1·635, β 1·650, γ 1·655; γ—α 0·020. The angle γ:c = 18° and 2V 60°±1° Pleochroism follows the scheme α pale yellow, β dirty bluish-green, γ deep bluish-green, with absorption γ > β > α.
Sapphirine crystals from Blinkwater, Transvaal
Authors: Mountain Edgar D. 
Published: December 2006

Some time ago, Mr. F. C. Partridge, Mineralogist to the Geological Survey of South Africa, gave me some crystals of sapphirinc which he thought might be of interest for goniometric examination. They come from the farm Blinkwater 1037, about 47 miles NNW. of Pietersburg and 45 miles WSW. of Louis Trichardt in northern Transvaal, and were collected by him in July 1930, after he had identified some specimens of sapphirine sent to him by Mr. A. Ruskovitch of Abrasive, northern Transvaal. They occur in a coarse granitic rock rich in brown mica, and are associated with small prismatic crystals of pink corundum.The sapphirine crystals are almost invariably tabular or platy in habit, although occasional crystals possess a rhomb-shaped cross-section. The largest crystal measures 50×35×5 mm., while the thickest one is only 7 mm. in thickness. They are generally six-sided in outline with a strong suggestion of orthorhombic symmetry.
The ‘baddelyite from Alnö’—an error
Authors: von Eckermann H. 
Published: December 2006

In most mineralogical text-books the nepheline-syenite area of Alnö, on the east coast of Sweden, is given as one of the few localities of the rare mineral baddelyite, ZrO2. This information is based on a communication by E. Hussak, who claimed to have discovered the mineral in jacupirangitic varieties of the Alnö nepheline-syenites.The present writer, being engaged with a petrological and mineralogical revision of the Alnö occurrence, earlier described by A. G. Högbom in his classic memoir of 1895, has in vain looked for the presence of baddelyite. Hussak claimed to have isolated by means of Klein's solution 0·38 gram of pure baddelyite from 100 grams of rock, as well as to have obtained characteristic ZrO2 crystals inn borax bead test. Repeated isolation tests with Clerici's solution on samples from various localities within the Alnö area, however, furnished nothing but residues of melanitic garnet.
On the relation of chamosite and daphnite to the chlorite group (With Plates XVIII and XIX.)
Authors: Hallimond A. F. 
Published: December 2006

There is a close optical and chemical resemblance between chamosite, the chloritic mineral of the bedded ironstones, and daphnite, a low-temperature vein-chlorite common in some of the Cornish tin mines. New material has made it possible to undertake a fresh comparison of the two minerals: chemical analyses have been made by Mr. C. O. Harvey, chemist to H.M. Geological Survey, and a report on the X-ray measurements is contributed by Mr. F. A. Bannister, of the Mineral Department of the British Museum.The new analysis of chamosite agrees with the simple formula previously assigned: X-ray examination of material from several localities has now established the distinctive crystalline nature of this fine-grained mineral, which differs structurally from ordinary chlorites such as clinochlore. Daphnite, on the other hand, has the ordinary chlorite structure, but the new analysis fully confirms Tschermak's original opinion that it cannot be represented chemically as a mixture of serpentine and amesite.
Petrological application of the low-power binocular microscope
Authors: Wells A. Kingsley 
Published: December 2006

In carrying out a petrological examination of pebbles collected by Mr. F. Gossling from the Lower Greensand of Surrey and west Kent, the writer has found a low-power dissecting binocular microscope an extremeIy useful piece of apparatus. The instrument, by Watson, is fitted with two pairs of objectives on a rotating nosepiece, and with two pairs of eyepieces, so that it commands the choice of four different magnifications.The pebbles are treated in a uniform manner. After the preliminary examination of a ‘bag’ of pebbles, those selected for study are ground flat on one side, finishing on the fine carborundum plate as if for section making. Each one is then mounted on the usual 3 by 1 inch glass slide, taking care not to over-cook the balsam. If the pebbles are treated systematically in batches of six, a dozen pebbles can be mounted in less than an hour, so that the gain of time over section-making is very considerable.
Occurrences of bavenite in Switzerland
Authors: Claringbull G. F. 
Published: December 2006

Bavenite was first described from Baveno by Artini in 1901 as monoclinic crystals of prismatic habit in pegmatitic druses in granite and given the formula 3CaO.Al2O3.6SiO2.H2O. More recently, the mineral has been described pseudomorphous after beryl from Himalaya mine, Mesa Grande, San Diego County, California, by Schaller and Fairchild (1932) and shown to contain beryllium as an essential constituent. In 1933 X-ray determinations by Ksanda and Merwin indicated a unit cell with dimensions a 9·67, b 11·53, c 4·95Å, and showed the symmetry to be orthorhombic and referable to the space-group V1, Vh1, or C2v1. Revised crystallographic orientation and optical constants were also suggested by these authors.The material about to be described is from two localities in Switzerland. Of fourteen specimens from a fissure in the rocks below the Muotta Nera, Piz del Laiblau, Val Nalps, Tavetschthal, Graubünden, selected by Mr. F. N. Ashcroft in 1935 and 1936 from a fairly large series stocked by Adolf Caveng of Sedrun, one (B.M. 1937,598) carries the mineral as roughly radiating aggregates of platy fibres of very pale brown colour in bulk.
The composite dike at Brockhill, Worcestershire (With Plate XXIII.)
Authors: Taylor J. H. 
Published: December 2006

At Brockhill in Worcestershire, some 11 miles west of Droitwieh, in the valley of the river Teme, a small dike of igneous rock is intruded into the red marls and sandstones of the Downtonian Series.The dike was figured and described by Phillips in 1848. On the Old Series one-inch Sheet 55 N.E. it was indicated as having a very limited outcrop on the eastern side of the river Teme; but a report of an excursion to Brockhill in 1874 records the presence of igneous rock on the opposite bank. The intrusion was examined during the resurvey on the six-inch scale of the New Series one-inch map, Sheet 182 (Droitwich), and is of interest both on account of its petrographic character and its remoteness from other igneous rocks. It has recently been traced by magnetic methods for a distance of over three-quarters of a mile.
New refractometers employing diamond and other minerals
Authors: Anderson B. W. , Payne C. J. , Pike J. 
Published: December 2006

Direct-reading refractometers depend upon observation of the boundary between transmission and total internal reflection, when a flat surface of a specimen is placed in optical contact with the flat surface of the isotropic medium employed in the instrument. This medium is usually a heavy lead glass in the form of a hemisphere or prism. The upper limit to the range of indices which can be measured is determined by two factors: the refractive index of the medium employed in the instrument, and the refractive index of the liquid used to make optical contact between the two surfaces.Liquids of high refractive index are essential to such instruments, and some reference to them may be conveniently made at this stage. Various pure liquids, mixtures, and melts of high refractivity have been proposed from time to time, chiefly as immersion media.
Colloidal gold as a colouring principle in minerals
Authors: Friend J. Newton , Allchin John P. 
Published: December 2006

Many attempts have been made to discover the causes of the various colours displayed by minerals. If we except fluorescence and allied phenomena, the diiteren~ theories advanced may in general be grouped under one or other of the following classes:(1)Colour may be due to an intrinsic property of atoms, ions, or molecules. Examples are copper atoms, chromate ions, and ferric oxide molecules.(2)Colour is sometimes attributed to structural causes. The blue tints of certain halites have been explained in this way; but a fresh suggestion is made in this communication.(3)A pigmentary impurity may cause the observed colour. The colour of the ruby is believed to be caused by the presence of a red chromic oxide. The blue tint of a Yorkshire aragonite is shown later to be due to a copper salt.(4)Some minerals show plays of colours due to interference and/or grating effects. Labradorite and opal are cases in point. Into this group also fall minerals like bomite which become iridescent from tarnish.
The selenium and tellurium contents of sulphur from Krisuvik, Iceland
Authors: Friend J. Newton , Allchin John P. 
Published: December 2006

The deposits of sulphur at Krisuvik, Iceland, have long been known. They were described geologically in detail by Vincent who also discussed their probable origin, but gave no chemical analyses other than rough determinations of the percentages of sulphur and matrix in various samples. From the flame spectrum Vincent thought that thallium might be present.Apart from popular descriptions by travellers and casual references in guide-books, little attention appears to have been given in literature to these deposits in more recent years. Sporadic attempts at working the sulphur economically were made by the Danish Government during the eighteenth century and later by a Danish merchant round 1832. These were abandoned, however, owing to cost of transport. There is little likelihood of their renewal in the immediate future unless the deposits are found to contain some other element(s) of sufficient market value.
Observations on the alteration products of stibnite
Authors: Schoeller W. R. 
Published: December 2006

In the mineralogical literature, stibnite is usually stated to change by oxidation into kermesite and finally into valentinite or senarmontire. Another alteration product is described as antimony ochre, a term loosely applied to several minerals, viz. cervantite, stibiconite, and volgerite (Dana, System of mineralogy, 6th edit., 1892, p. 203).In my metallurgical experience with stibnite ores, I have never met with kermesite or valentinite. Whenever I have encountered altered stibnite in ores from widely separated localities, it showed a yellowish to buff coating which I took to be cervantite. After spending two years in central China where I examined hundreds of tons of stibnite ores from Hunan province, I had to purchase a specimen of kermesite from a mineral dealer in order to become acquainted with the mineral. The locality of the specimen was given as Bräunsdorf, Saxony.
The determination of ferrous iron in resistant silicates
Authors: Hey Max H. 
Published: December 2006

The determination of ferrous iron in minerals, such as staurolite and kornerupine, which cannot be effectively dissolved by dilute sulphuric and hydrofluoric acids has been made possible on the macro-scale by the work of H. P. Rowledge; the mineral is fused with sodium fluoride and boric oxide at 900°C. in a sealed pyrex glass tube, the fusion cake dissolved in hot dilute sulphuric acid in a current of carbondioxide, and the solution titrated with potassium permanganate. We have met with no difficulty in applying the method on the macro-scale, but when only small amounts of a mineral are available several difficulties arise, and modifications become necessary.The air present in the sealed tube of a Rowledge fusion, using the quantities and dimensions he specifies, is already sufficient to oxidize about 3 to 5 mg. of ferrous oxide. But when the weight of the sample is reduced to 10 mg., it is not possible to reduce the dead-space in the tube in proportion ; it can hardly be reduced below about ¼c .c. which is sufficient to oxidize 0·3 mg. or 3% FeO and is likely to be more effective in this direction than on the larger scale, since the surface of the fusion is proportionally greater.