bluuebunny/crossref_metadata_2025_split huggingface dataset:
On a Specimen of Proustite containing Antimony
Authors: Miers H. A. , Prior G. T. 
Published: December 2006

The specimen which is the subject of the present note is a magnificent piece of Proustite from Chañarcilio, Chili, which has been recently acquired for the British Museum. It is a mass of lustrous crystals, measuring about 3 inches by 2½ inches, and nearly 3 inches in height.The specimen has a peculiar cockscomb appearance, due partly to the habit of the crystals and partly to the way in which they are grouped ; the lower part consists of Proustite, interpenetrated by a little minutely crystalline white Calcite, which on one side of the specimen extends partly over the crystals in the form of darker coloured acute rhombohedra.
On the Polysynthetic Structure of some Porphyritic Quartz Crystals in a Quartz-felsite
Authors: McMahon C. A. 
Published: December 2006

Before describing some features of special interest in the microporphyritic quartz crystals of an Indian felsite, it may be as well to say a few words, by way of preface, regarding the rock itself.About 85 miles to the north-west of the town of Delhi, in the peninsula of India, a hill rises abruptly from the plain to the height of 630 feet. It is one of a series of similar elevations separated from each other by some miles of sandy soil which strike the traveller with their resemblance to a group of islands in a tempestuous sea—an idea greatly favoured by the long swelling waves into which the sand is thrown by the strong westerly winds which prevail in that region during the greater part of the year.
On Struvite
Authors: Solly R. H. 
Published: December 2006

At a meeting of the Cambridge Philosophical Society on May 20th, Mr. Robinson read a preliminary paper "On the formation of Struvite by Micro-organisms.""The author had observed the formation of fine well-formed crystals in many tubes of nutrient gelatin and agar-agar, in which he was growing pure cultivations of various micro-organisms."
The Hemimorphism of Stephanite: the crystalline form of Kaolinite
Authors: Miers H. A. 
Published: December 2006

Stephanite has been the subject of two important memoirs. Schröder examined minutely the crystals from Andreasbcrg ; Vrba has described fully the character of the stephanite from Przibram and other localities, and has given at the same time a summary of the observations of previous mineralogists, so that his memoir constitutes a monograph of the mineral.
By neither of these observers, however, nor elsewhere, has it been stated that stephanite is hemimorphic, although it has been suspected of being possibly hemihedral.
It is the object of the present paper to establish the hemimorphism of stephanite upon evidence similar to that which has been employed in the case of pyrargyrite.
On the Mexican Meteorites, with especial regard to the supposed occurrence of wide-spread meteoritic showers
Authors: Fletcher L. 
Published: December 2006

In a receipt paper descriptions were given of some meteoritic masses, which had been brought from the Desert of Atacama and are now in the British Museum. Several of them were independent of those preserved in other Meteorite Collections, in that they showed no signs of having been broken since their discovery; but it still remained to determine whether they might not possibly belong to meteoritic showers, of which individual masses had been already collected and described.For this a minute investigation of the meteoritic literature of the Desert of Atacama was necessary.
Sanguinite, a new Mineral; and Krennerite
Authors: Miers H. A. 
Published: December 2006

This mineral was found upon several specimens of argentite from Chañarcillo which were acquired for the British Museum in 1886.The specimens consist of argentite in large drusy octahedra implanted on quartz or calcite, and associated with proustite and a little asbestos.The proustite is mostly in the form of small brilliant prisms with sealenohedral terminations {201̅}, capped by the rhombohedron {110}, which are grouped upon the argentite. But dispersed on the argentite, together with these crystals of proustite, are a number of fine glittering scales, which present at first sight precisely the appearance of the pyrrhosiderite or göthite of Siegen, having the same bronzy red colour, and a lustre resembling that of earthy haematite when seen on the matrix, that is to say partly by reflected and partly by transmitted light. Under the microscope the scales are easily distinguished from göthite ; they are without striations, remain dark when rotated between crossed nicols, and appear of a nearly blood-red colour by transmitted light ; whereas scales of göthito are striated in one direction, and exhibit marked differences of absorption when rotated above the polariser.
Cassiterite, “Sparable Tin,” from Cornwall
Authors: Solly R. H. 
Published: December 2006

During the last few years some fresh specimens of Sparable Tin have been raised from various mines in Cornwall; a description of this variety may therefore be of interest to the Society.The value of this description of the now finds will perhaps be increased by combining with it an account of the specimens of Sparable Tin from different mines now to be found in our museums and private collections. Through the kindness of those gentlemen who own or have charge of these collections, I have been enabled to see and examine many of the interesting specimens which they contain.The name "Sparable Tin" is peculiar to Cornwall, and has been given to this variety of Cassiterito on account of its so-called resemblance to the sparable nail of the cobbler.
A Student's Goniometer
Authors: Miers H. A. 
Published: December 2006

This instrument, which was designed for use in the Crystallographic Laboratory of the City and Guilds of London Institute (Central Institution), is in its simplest form (Plate III.) a strong and inexpensive Wollaston Goniometer. It is, however, constructed in such a way that it may be converted into an instrument of greater precision (Plates IV. V.) by the simple addition of accessory parts to tho apparatus of Plate III. without any previous alteration.L is the graduated disc, and B the milled head by which it is turned; the vernier v is not the slender tongue of metal which is usual in such instruments, but is engraved upon a portion of the fixed disc V; and L is kept in continual contact with V by means of a circular steel spring inserted between B and the bearing of the axle.
On a rapid method for the accurate recognition of sulphides, arsenides, antimonides, and double compounds of these bodies with metals
Authors: Burghardt Charles A. 
Published: December 2006

The process to be described has been applied to the minerals mentioned below, but I have no doubt that all similarly constituted minerals will also be easily recognised by the method.I am quite sure that all mineralogists have experienced much annoyance and difficulty in obtaining really satisfactory results with the ordihary blowpipe reactions in regard to some of the compounds of arsenic, antimony, and sulphur with metals, particularly in the separation of the metal or metals from the above-mentioned elements. In order to obtain the metal the assay requires a most careful and tedious roasting on charcoal in the oxidising flame of the blow-pipe, in order to volatilise away the sulphur, arsenic, or antimony. When this roasting is complete the residue (oxide) is mixed with either sodium carbonate, or that salt and cyanide of potas. slum, and fused for a considerable time on charcoal in the reducing flame in order to obtain a bead of the metal.
A System for constructing Crystal Forms by the Plaiting of their Zones
Authors: Gorham J. 
Published: December 2006

In this paper the author described his method of constructing crystal models of paper or cardboard by means of plaiting. In the ordinary crystal "nets" (such as, according to Mr. Gotham, were constructed by himself and shown at the Royal Society as early as 1847) the faces of the model are drawn in juxtaposition on cardboard and cut out, some of the lines being only partially cut through ; the net is then folded up so as to form a solid figure, and the faces are united at their edges by gum.In the models described and exhibited by Mr. Gotham, the faces are so drawn as to be disposed along strips; these strips are united to each other at one end, and can then be folded together by a process resembling plaiting, in which the strips pass alternately under and over each other.
On the Occurrence of an Aluminous Serpentine (Pseudophyte) with flintlike appearance near Kynance Cove
Authors: Fox Howard 
Published: December 2006

Kynance Cove lies in the midst of a Serpentine District. The Serpentine is associated with some little hornblende schist in the cove, and is traversed by black dykes both porphyritic and non-porphyritic from a few inches to several feet thick, by granitic veins, as also by veins of saussuritic gabbro, which latter are, however, of rare occun'ence on the western side of the Lizard.When looking due east from the middle of Kynanee Sands a rectangular block of white rock is seen in the dark red serpentine cliff from 70 to 80 ft. above the sea-level at low water, and about 200 yds. from the spectator. The vein that gives rise to this block can be easily reached by crossing the stream that enters the cove from the east, climbing the rising ground, and after reaching a ridge about 100 yds. from the stream, descending the grassy slope to the right to a point about 9.00 yds. south-east of Oliver's Refreshment House. Here, a few feet below the grass, a block of rock is seen 4 ft. high, 6 ft. through in front, and covered by broken serpentine behind.
On the Pinite of Breage in Cornwall
Authors: Collins J. H. 
Published: December 2006

It has long been known that several of the felspar-porphyry dykes (Elvans) of the West of Cornwall contain crystals of pinite--apparently pseudomorphous after iolite--as an accessory mineral, and similar crystals occur.in the granite in several places.In the parish of Breage there are several of these dykes running towards the sea in a south-easterly direction, which are somewhat largely used as road-material. That which reaches the sea at Praa is in places thickly charged with the pinite crystals, and the same in a somewhat less degree may be said of the dyke which passes from the village of Trew through Great Wheal Fortune.
On Homogeneous, Structures and the Symmetrical Partitioning of them, with Application to Crystals
Authors: Barlow William 
Published: December 2006

SummaryThe above investigation shows:— 1.The nature of homogeneity of structure, and the properties which distinguish it from structureless homogeneity. The new definition of a homogeneous structure recently put forward by the author in Groth's Zeitschrift is given.2.A method of realising in a concrete form, and with great generality, the kind of repetition in space which constitutes homogeneity of structure, the models employed for this purpose each consisting of a number of similar plaster hands appropriately arranged in space.The total number of types of arrangement, all of which can be represented in this way, is 230, this being the number of typical point systems described by Fedorow and Schönflies, derived by their extension of Sohncke's methods. The various types of homogeneous structure, like the corresponding point-systems, all fall into the 32 classes of crystal symmetry.3.What property common to all homogeneous structures whatever most nearly coyresponds to Thomson and Tait's definition of homogeneity.4.Reasons for regarding as untenable the arguments put forward by Fedorow in support of his recent attempt to select from among the types of homogeneous structure those which are possible for crystals, and to determine the shapes of their ultimate units.5.The possibility of so classifying all conceivable ways of symmetrically partitioning all the types of homogeneous structure as to avoid all reference to the nature of the cell-faces, whether plane or otherwise, and, in other respects also, be perfectly general. Some reasons for undertaking this classification, notwithstanding its complexity, are given, the chief one being the relation of symmetrical partitioning to some stereo-chemical and other experimental facts.
Notes on a Biotite-Cyanite-Cordierite-rock from the Upper Satlej Valley, N.W. Himalayas
Authors: McMahon C. A. 
Published: December 2006

Some years ago I found in the bed of the Satlej at Wangtu, in the N.W. Himalayas, about 80 miles, as the crow flies, north-east of Simla, a boulder of the rock described in the following pages, It is composed of biotite, cyanite and cordierite, with apatite and rutile as accessory minerals.The specimen has a specific gravity of 2.92. Its structure is holocrystalline, and its minerals show no trace of parallelism in their orientation. It is, I think, a product of contact metamorphism.
Note on the Occurrence of Rocks Allied to Monchiquite in the Island of Fernando Noronha
Authors: Prior G. T. 
Published: December 2006

The name of Monehiquite, first applied by Rosenbusch and Hunter (Tscherm. Min. Mitth. XI. 1890, p. 445) to a peculiar group of dyke rocks tound in association with elæolite syenite in Brazil, is rapidly becoming familial" to petrologists through the discovery of similar rocks from various other localities.The Brazilian Monehiquites were described by Rosenbusch as black to grayish-black rocks, consisting of porphyritic ohvine and pyroxene, with widely varyiug amounts of hornblende and mica, in a glassy base usually crowded with hornblende microliths.
The “Satin Spar” of Alston in Cumberland; and the Determination of Massive and Fibrosus Calcites and Aragonites
Authors: Spencer L. J. 
Published: December 2006

Owing to the fact that aragonite frequently occurs in fibrous aggregations, as in "flos ferri,' it seems to have been sometimes assumed that all fibrous specimens of calcium carbonate are aragonite.On these grounds the " satin spar" from Mston Moor in Cumberland is often referied to aragonite, although it has more than once been shown to be really calcite. Miller refers to it under aragonite, as being from "Dufton in Cumberland, '' saying that it contains 4.25 per cent. of manganese carbonate: these figures are those given by J. Holme in a very crude analysis of the satin spar of Alston.
An Occurrence of Prehnite in Wales
Authors: Harrison W. Jerome 
Published: December 2006

The little land-locked harbour of Pwllheli in Caernarvonshire owes its existence to a boss of igneous rock, which forms a natural breakwater, and which is known in Wales as the " Gimlet Rock."The large quarries afford excellent exposures of the rock, which is worked into " setts " and used largely for paving purposes in the large towns of Lancashire, etc. It is a coarse ophitie dolerite, in which the augite is a very conspicuous mineral. The rock is traversed by many segregation veins, and is much jointed. The faces of the larger jointplanes are covered with crystals of quartz, calcite, a little natrolite, brookite and prehnite. But the three last-named minerals are of rare occurrence, and are always associated with quartz.
On some lead minerals from Laurium, namely, Laurionite, Phosgenite, Fiedlerite, and (new species) Paralaurionite
Authors: Herbert Smith G. F. , Prior G. T. 
Published: December 2006

In this paper are embodied the results of an examination of the specimens of lead slags from Laurium in the British Museum. On some of the specimens a new mineral, paralaurionite, was found, which possesses the same chemical composition as laurionite, but entirely different morphological and optical characters.In addition to crystals of the four minerals given in the title, a few crystals oi matloekite and anglesite were noticed, and on one specimen there is a radiating group of prismatic crystals of penfieldite.
On a mass of Meteoric Iron from the neighbourhood of Caperr, Rio Senguerr, Patagonia
Authors: Fletcher L. 
Published: December 2006

In the month of September, 1869, Captain Musters, who was st that time making an expedition through Patagonia, had his attention called to a heavy mass of material which he took to be marble. In the account of his journey he afterwards wrote (from memory) as follows:—"There is in this place, which is called by the Indians Amakaken, a large spherical boulder of marble, which it is the custom of the Indians to try their strength by lifting. Casimiro informed me that this stone had oeen there for many years, and the custom was very old. It was so large and heavy that I was just able to grasp it with both arms and raise it to the level of my knees, but some of the Indians managed to lift it to their shoulders."
Communications from the Oxford Mineralogical Laboratory. On the constitution of the natural Arsenates and Phosphates. Part III. Plumbogummite and Hitchcockite
Authors: Hartley E. G. J. 
Published: December 2006

The present paper deals with the somewhat obscure lead aluminium phosphates, of which the following varieties have hitherto been described :—(i)The original plumbogummite, a mineral found at Huelgoat in Brittany, and at Nuissière, Dept. Rhône.(ii)Some varieties of pyromorphite, containing alumina and water as constituents. These pyromorphites occur also at Huelgoat, and are usually quoted in books on Mineralogy as plumbogummite, although Damour, in his original paper on the subject, clearly distinguishes between the true plumbogummite and the aluminous pyromorphites.(iii)The American mineral, bitehcockite, occurring in the Canton Mines, Georgia.(iv)A Cumberland mineral, which for some time was mistaken for zinc silicate, but has recently been shown to be a phosphate of lead and aluminium (Miers, Min. Mag. 1896, XI, 272).
Petrographical Notes on the Rock-Specimens collected in the Little Island of Trinidad, S. Atlantic, by the Antarctic Expedition of 1839–43, under Sir James Clark Ross
Authors: Prior G. T. 
Published: December 2006

The Little Island of Trinidad, as it is called to distinguish it from the larger island in the West Indies, is situated in the South Atlantic Ocean, about 700 miles off the coast of Brazil, in lat. 20°31' S. and long. 29°19' W.According to Ross, who in 1839 effeeted a landing on tile N.W. coast, the island is a mass of volcanic matter, the rocks of which it is composed assuming the most extraordinary shapes. The most remarkable of these are the Sugar Loaf Hill on the southern and the Nine-Pin Rock on the north-western coast.
The alteration of Pyrite by underground water
Authors: Evans John W. 
Published: December 2006

It has for many years been proposed to form a reservoir with an area of some 36 square kilometres for irrigation purposes near Hiriyur in Northern Mysore, by erecting a dam at Marikanave, where the River Vedavati or Hagari crosses a rocky ridge running north-north-west and south-south-east.Doubts were raised as to whether the rock would form a sufficiently firm foundation, but Mr. Robert Bruce Foote, late Superintendent of the Geological Survey of India, and my predecessor as State Geologist in Mysore, reported that it was in every way suitable for the purpose.
A simple proof of the rationality of the anharmonic ratio of four faces of a zone
Authors: Hilton Harold 
Published: December 2006

The anharmonic ratio here considered is that of the pencil (P) formed by the four lines (lying in a plane perpendicular to the zonal axis) drawn from any point M perpendicular to four faces of the zone. The anharmonic ratio of the pencil P is evidently independent of the position of M.Let four planes be drawn through M perpendicular to the four lines of the pencil P; these are parallel to the crystal faces and meet in a line (the line through M perpendicular to the plane of the pencil P and parallel to the zonal axis).These four planes are cut by the plane of the pencil in a pencil having the same angles, and therefore the same anharmonic ratio, as the pencil P.
Sulpharsenites of lead from the Binnenthal with Plate III
Authors: Solly R. H. 
Published: December 2006

Baumhauer, 1896, Zeits. Kryst. Min. XXVI, 598-602. Crystallography. with Analysis by Bömer. (Abstract Min. Mag. XI, 225.)Jackson, 1900, Min. Mag. XII, 287. Analyses.System : Rhombic. a : b : c = 0·4782 : 1 : 0·5112.These ratios are calculated from 010 : 350 = 51°7′ and 010 : 111 = 70°45′ measured On crystal No. 1 (see p. 81). A new orientation has been chosen for the crystals, so that the well-developed prism zone is vertical, and the cleavage plane, (001) of Baumhauer, becomes (010) to correspond with the cleavage of jordanite. The parametral plane has also been changed, chiefly on account of the pyramid planes.
Sulpharsenites of Lead from the Binnenthal. Part III.—Baumhauerite, a new mineral; and Dufrenoysite
Authors: Solly R. H. , Jackson H. 
Published: December 2006

For this new mineral I propose the name baumhauerite in honour of Dr. H. Baumhauer, Professor of Mineralogy in the University of Freiburg, Switzerland, who has done so much to elucidate this complicated group of sulpharsenites of lead.System: Oblique. a : b : c = 1.136817 : 1 : 0.947168; β = 82° 423/4.These elements are calculated from the angles 100 : 101=50° 27′ 101:001 = 32° 153/4′ and 010 : 111̄ = 50° 33′ measured on crystal No. I.The crystals closely resemble dufrenoysite and jordanite in appearance. They may be distinguished from dufrenoysite by the marked oblique development of the zone [100,001], and from jordanite by the absence of twin striations and by the colour of the streak. The edges in the pyramid zone and between planes in the zone [100,010] are more or less rounded.
The Cerargyrite Group (holohedral-cubic silver haloids)
Authors: Prior G. T. , Spencer L. J. 
Published: December 2006

Historical Introduction.—As given in modern text-books, the holohedral-cubic silver haloids occurring as minerals include the following species: the pure chloride, chlorargyrite, AgCl. ; the pure bromide, bromargyrite, AgBr; the intermediate embolite, Ag(Cl,Br), containing chlorine and bromine in varying proportions ; and iodobromite, containing all three halogens in a definite ratio corresponding to the formula 2AgCl.2AgBr.AgI.The terms hornsilver (used by Gesner as far back as 1565) and cerargyrite (Beudant, 1832) are usually taken as referring only to the pure chloride. As regards their signification, however, they are equally applicable to all of the above species, and in lack of chemical analyses were certainly so applied in the past. Thus Breithaupt, after the discovery of the bromide and chloro-bromide of silver by Berthier in 1841 and 1842, remarks that many of the specimens of ‘Hornerz’ in the Werner Museum having a greenish colour probably contained bromine.
Note on Mica (Fuchsite) as a decorative stone used by the ancients
Authors: Miers H. A. 
Published: December 2006

The specimen to which the following note refers was found in the Oxford Collection, and nothing is known of its origin.It is a polished piece of translucent emerald-green stone, with patches of darker green and also patches of a dull brown colour.The stone has taken a high polish, and brilliant internal reflections from immediately below the surface of the paler portions give it in those parts almost the appearance of a flawed emerald. But the fractured surface shows it to be merely a massive, pale green, micaceous mineral with brown patches, which appear at first sight to be only an iron-stained variety of the same substance.
Note on rare twins of Calcite from Somerset
Authors: Bowman H. L. 
Published: December 2006

The crystals to which this note refers, occur in a quarry in the New Red Sandstone at Bindon, in Somerset, on the property of Mr. H. H. Worthington, and were presented to the Oxford Museum a few months ago by his son, Mr. J. H. Worthington. I have lately had an opportrinity of visiting the locality and examining the mode of occurrence of the specimens.The crystals have all been obtained from a single, roughly vertical vein in the side of the quarry, which shows an exposure of irregularly alternating beds of red sandstone and conglomerate. The pebbles of the latter consist, for the most part, of a compact purplish limestone, while a few are of greasy-looking quartz.