bluuebunny/crossref_metadata_2025 huggingface dataset:
Notes on Northern Minerals
Authors: Wallace Thos.
Published: December 2006

My attention was first directed to this rock by Mr. Cruickshank, clerk of works at Beaufort Castle, in July of last year, when, from the description he gave of it, I ventured to pronounce it barytes. Specimens were soon after this put into my hands by Mr. Cruickshank, when I found that my conjecture was a correct one. There was another mineral associated with the barytes, of which we will speak afterwards. The specimens received were so very fine, that I resolved to visit the locality to be able to describe its surroundings and procure specimens for myself. This I did in May last in company with two of my colleagues and Mr. John Ross, one of Lord Lovat's gamekeepers, and who I believe was the first to call attention to this new locality.
On the Chemical Composition of Butyrellite (Dana)
Authors: Ivison Macadam W.
Published: December 2006

In dana's System of Mineralogy, 5th Edition, 1883, page 747, the following description of this substance is given :—" Crystallisable in needles; butter-like in consistence; colour, white; melting point of impure native material, 47°, Brazier; but of material after solution in alcohol, 51°, Luck ; 52°-52°· Brazier ; easily soluble in alcohol or ether."
On an Occurrence of Rare Copper Minerals from Utah
Authors: Mackenzie G. S.
Published: December 2006

In the American Eagle Mine, Utah Territory, occur in intimate association with olivenite and other copper compounds, two copper minerals of an interesting and rare composition.

Covering the surface of often large pieces of more or less friable mixed arseniates, sometimes forming a complete green coating, are numbers of beautiful emerald-green globules. In consequence of the firm adherence of the base of the globules to the underlying gangue matter, it was difficult to obtain material pure enough for analysis, and therefore the results given below lay no claim to great accuracy.
Address to the Mineralogical Society
Authors: Bonney
Published: December 2006

It does not appear to be at present a matter of fixed precedent whether the Annual Meeting of the Mineralogical Society should or should not be associated with the delivery of a Presidential Address ; and I had hoped, knowing how slightare my claims to the honour which you have conferred upon me, to have escaped until I give place to a worthier successor. But our Honorary Secretary has intimated to me that he would prefer 'a few remarks' and as I feel so strongly the obligations under which he has placed the Society by the free gift of his valuable time, his will is law to me.
Fine Crystals of Pale Lilac Calcite from Tankerville Mine, near Shelve, Shropshire
Authors: Solly R. H.
Published: December 2006

The rare occurrence of the primitive rhombohedron r {100} with little or no modification on crystals of calcite has induced me to bring to the notice of the Society some very fine pale lilac crystals exhibiting this unusual habit.

These specimens were raised a few years ago from the Llandeilo flags strata in the Tankerville lead mine, near Shelve, Shropshire.
Description of a Crystal of Parisite
Authors: De Grandmaison Guyot
Published: December 2006

Occurrence. At the Emerald Mines of the Valley of Muso, New Granada, in a gangue composed of anthracitic calcite and pyrites. Lustre, vitreous to resinous ; colour, yellowish brown to honey-yellow. An acute hexagonal pyramid with striations perpendicular to the axis. The crystal measures 84 millim. in length, and 12 millim. in thickness at the base.

The pyramid is perfect and its apex is intact.

All the specimens of Parisite which have been hitherto received, and are found in European Museums, exhibit a truncated hexagonal pyramid. This section is due to a very easy basal cleavage.
Notes on Minerals from Cornwall and Devon
Authors: Solly R. H.
Published: December 2006

I obtained this summer a most beautiful variety of fluor spar, which was raised from the 145 fathom level of the Holmbush Mine. It is of a transparent azure-blue colour, and shows well marked fluorescent phenomena, though not so strongly as that of Weardale, Cumberland.

Some of the specimens are deep blue in one part and limpid like glass in another ; it was found that while the deeply coloured part was strongly fluorescent the limpid part had little or no effect upon the refrangibility of the light passed through it.
Some Results of the Crystallographic Study of Danburite
Authors: Schuster Max
Published: December 2006

Every student of crystals is aware how frequently they fall short of the ideal perfection which theory ascribes to them. With regard to the development of the simple forms, the irregularities are most prominent on the crystals which are subject to certain laws of symmetry. In consequence of the differences of size presented on the same crystal by planes belonging to the same form, the most manifold distortions ensue, resulting at one time in the imitation of forms of a lower degree of symmetry, at another in the complete absence of symmetry. Moreover, as long as the faces constituting the distorted form remain the same, i.e. as long as the cause of the distortion is without influence on the development of the combination, so long will the angles of inclination of the circumscribing elements of the individual remain the same, and thus the degree of symmetry can be determined by measurement of the crystal notwithstanding the distortion.
On a Glaucophane-eclogite from the Val d'Aoste
Authors: Bonney T. G.
Published: December 2006

The number of localities at which glaucophane has been discovered is still comparatively small, so that it may be of interest to add another and to describe the microscopic structure of a rock in which this interesting variety of hornblende occurs.

The carriage road between Vertex and St. "Vincent in the Val d' Aoste mounts along the left bank of the Dora Baltea, which, in one part, often called the defile of Mont Jovet, is scarped and craggy. The steepest part of the ascent is between the hamlets of Berrioz and Nus (?). I was walking up this, one day in July 1885, in company with my friend the Rev. E. Hill, F.G.S., when my eye fell upon a rock, which I at once reeognised as a variety of eclogite, composed chiefly of small reddish garnets and dull-green hornblende. We secured specimens, though with considerable difficulty, for the rock was very tough ; made a few observations and passed on.
On Idocrase and other Minerals recently found near Zermatt
Authors: Lewis W. J.
Published: December 2006

Some Zermatt Guides (Joseph Taugwalder and his brother) made, on a recent excursion up one of the mountains (Pollux ?) in the neighbourhood, the discovery of some very interesting crystals of idocrase and red garnet.

The idocrase crystals are of a dark sherry eolour, and are developed in simple forms, the prism-planes m{110}, a{100}, and the base c{001}, being well developed. The edges [cm] are truncated by narrow planes u{111}, and at the corners small planes i{312} are sometimes found. The prism planes are deeply striated, and at the same time the c plane shows more or less coarse squares, which sometimes seem to belong to independent crystals. The sides of the square are parallel to the a {100} faces. The crystals have, therefore, much the character of a bundle of thin pyramidal crystals united together in parallel positions.
The Metallic Ores of Chili
Authors: Kerr John F.
Published: December 2006

The ores which I have the honour to submit for your inspection were collected by me in Chili. They consist of numerous compounds of copper, silver, gold, &c., and represent the very varied minerals obtained in that country.

Besides the primary metal there is usually at least one secondary body of value present.

The proportion in which this secondary metal—I mean secondary as regards quantity—is present in metallic ores does not seem to be a mere chance affair, but seems to follow some law. My attention was directed to this matter by the silver ores from the district of “Lomas Bayas” near Copiapó. These ores contain gold in a certain proportion, not in relation to the gross weight of the ore but to the contents in silver.
New Localities for the Mineral Agalmatolite, with Notes on its Composition
Authors: Bell William Hamilton
Published: December 2006

The rock-like mineral, known as Agalmatolite, derives its name from the Greek word aγuλμa, an image. It has also received the trivial name of Pagodite from Pagoda ; it having been long used by the Chinese as the substance from which they carve their images and pagodas.

The earlier mineralogists confined the above names to hydrated silicates of alumina and potash, doubtless a product of the decomposition, or alteration, of orthoclase felspar ; an intermediate stage in its conversion into the kaolin which is so abundant in the Celestial Empire.

Jameson, Phillips, Allan, Nicol, and all the fathers of mineralogy, admitted no other substance under the name. Nicol, who was a thoroughly well-read mineralogist, writes : “Many substances are named Agalmatolite which are really distinct;” and he clearly defines the species, which he makes the same as that called Agalmatolite in the present communication.
On a New Locality for Agalmatolite
Authors: Macadam W. Ivison
Published: December 2006

The specimens to which this note refers were obtained from a precipitous cliff at the north-west end of Loch Maree, Ross-shire, called Creag Mhôr Thollie. The mineral occurs on the 1,000 ft. contour to tile east or loch side of the Creag, and is in quantity.
On the Chemical Composition of the Mineral Bruiachite, found by Mr. Thomas D. Wallace, of Inverness, at Loch Bhruithaich, Inverness-shire
Authors: Macadam W. Ivison
Published: December 2006

In a paper read before this Society on June 16th, 1885, Mr. Wallace drew attention to this mineral as being found at Loch Bhruithaich, and stated that it was obtained incrusting Barytes.

The mineral is clear, beautifully crystalline, with a tendency to a bluish tinge of colour, and very friable.
Barytes from Addiewell, West Calder, in Midlothian
Authors: Trechmann Charles O.
Published: December 2006

This occurrence of barytes is somewhat remarkable and interesting from several aspects :—The peculiar conditions under which it seems to have been deposited, the limited quantity, and the perfection and richness of the crystallographic development.

It was found some two years ago in one of the shale pits of the Young's Paraffin oil Company, and my friend Mr. J. S. Thomson, to whom I am indebted for two of the four or five existing specimens (of which one, I am happy to say, has been deposited in the Museum of Edinburgh), was so kind as to procure for me from the Mining Engineer of the Company a sketch of the Geological Strata of the neighbourhood, in which the position of the beds containing the crystals is indicated (Plate II.).
Two Analyses of Crystals of Apatite
Authors: Robinson Henry
Published: December 2006

The three varieties of apatite at present known to occur in Cornwall are the sea-green limpid crystals from St. Michael's Mount and other places, the dirty-white, semi-opaque, hexagonal prisms associated with axinite from Botallack Head, and the thin hexagonal plates, described and analysed by Prof. Maskelyne and Dr. Flight as coming from a new locality, now known, however, to have been obtained by the late Mr. Tailing from Fowey Consols, and previously noted from this mine by Greg and Lettsom. To these must now be added a new variety which was lately brought to me as chalybite from the deep workings of Levant Mine, St. Just. The specimens are closely analogous to those analysed by Dr. Flight, but differ slightly in chemical composition and mode of occurrence.
On a New Variety of Mineral from Cornwall
Authors: Kinch E. , Butler F. H.
Published: December 2006

Some two years since the authors received from East Cornwall examples of a erystallised mineral presenting features dissimilar to those of any species previously known to them, but presumably referable to Dufrenite. The specimens obtained were from the central part of a narrow neck of "dead ground" (compact ferruginous quartz rock) connecting the much broader E. and W. continuations of a lode, yielding respectively copper and tin ores.

The freshest crystals have a vitreous lustre, and vary in colour from almost black to a light apple-green, their sections, however, being of a yellow brown to yellow. Where, as commonly, some superficial chemical change has taken place—seemingly into limonite—the colour is from red to brown or yellowish brown.
Cassiterite of the Straits Settlements
Authors: Hampton J. H.
Published: December 2006

The tin from the Straits Settlements has hitherto been solely derived from the alluvial deposits, and is consequently in the form of alluvial or "stream" tin—each grain of Cassiterite being separate, and in many cases so considerably water-worn as to afford evidence of its having been washed down for a considerable distance; the angles of the grains having given place to smooth surfaces during their deposition.

The largest grains occur on the tops of some of the hills, with a diminution in size noticeable with distance from the hills.
On the Occurrence of considerable deposits of Limonite (Bog Iron Ore) in North-west Ross-shire
Authors: Macadam W. Ivison
Published: December 2006

During the course of an inquiry into the nature and extent of the less known iron ore deposits of Scotland undertaken in connection with a paper to be communicated to the Society of Antiquaries of Scotland during the Winter Session 1886-87, I have been led to consieler certain masses of Bog Iron Ore which are distributed somewhat widely over the less cultivated portions of the country. The present communication deals only with the north-westerly portion of Ross-shire, and most of the localities are within the parish of Gairloch.
Further Note on Agalmatolite in Gairloch Parish, Ross-shire
Authors: Macadam W. Ivison
Published: December 2006

In my previous communication I drew attention to an impure variety of Agalmatolite found on Creag Mhôr Thollie, and which contained an excess of silica. A similar body was referred to in connection with Mr. Hamilton Bell's paper on "New Localities for Agalmatolite" as having been obtained from Ballater Pass. In connection with the material obtained at Creag Mhôr Thollie, I expressed the opinion that the agalmatolitie mineral had been formed in the presence of an excess of silica which had become combined with the other ingredients, forming what I then termed a "Siliceous Agalmatolite."

During the past summer I have again had an opportunity of examining the Creag, and towards the northmost end found very large masses of the pure mineral.
Note on the Identification of the Scotch and New Brunswick “Albertites”
Authors: Honeyman D.
Published: December 2006

Prof. Tennant, of London, and I, identified the two "Albertites " in 1862. I was then a Commissioner for Nova Scotia at the Great Exhibition. In the ncighbouring Court of New Brunswick there was a tub full of specimens of Albertite, which were freely given to visitors by Mr. Daniel, the Commissioner for New Brunswick, and myself.

It was, therefore, no astonishment when the Professor's assistant put into my hand a piece of "Albertite" as I entered the shop, and asked me what I thought of it. I said, "It is a piece of our New Brunswick Albertite." He replied, it was not from New Brunswick, but from some part of England, and showed me a boxfull that had just been received. The only guide to the locality whence it came were the markings on the lid of the box—" Aberdeen Railway" and Kiltearn.
On a Meteoric Iron found in 1884 in the Sub-district of Youndegin, Western Australia, and containing Cliftonite, a cubic form of Graphitic Carbon
Authors: Fletcher L.
Published: December 2006

This iron was found on January 5th, 1884, by Alfred Eaton, a mounted police constable, when on duty in the sub-district of Youndegin, at a spot distant about 60 chains (three-quarters of a mile) in a north-west direction from the top of Penkarring Rock, and roughly estimated by him as 70 miles east of York, Western Australia; this must be about longitude 117°30', E. of Greenwich, latitude 31°30' S. Only one of four observed fragments having been brought in by Mr. Eaton, the late Captain Smith, Commissioner of the Police at Perth, sent him out to Penkarring with a native assistant with instructions to bring in the other three, at the instance of the Rev. Charles G. Nicolay, Curator of the Geological Museum, Fremantle, to whomthe late Mr. Edward T. Hardman, F.C.S., the Government Geologist, had expressed his belief in the meteoric origin of the iron.
Supplementary Note on Felspar from Kilima-njaro
Authors: Fletcher L. , Miers H. A.
Published: December 2006

A Chemical analysis of this felspar, to which our attention was directed by Professor Bonney, and which was subsequently described on crystallographic and optical grounds as orthoclase, shows it to be a sodapotash felspar of somewhat peculiar composition.

In the following table, the first two columns give the results obtained on analysis (Fletcher) of two loose crystals, of which the second was a twincrystal of lighter eolour than the first; the next two columns represent the same analyses if the oxide of iron (present as visible enclosures) and the loss on ignition are neglected; the numbers in the fifth column are obtained by taking the means of the numbers in the two preceding columns.
On the Occurrence of Greenockite at a New Locality
Authors: Heddle
Published: December 2006

More than a year ago I obtained a number of minerals in Boylestone quarry, which lies about a quarter of a mile north-west of Barrhead, near Glasgow.

Upon breaking up at home the very unwieldly druses which alone seem to occur at this locality, I found one which contained Greenockite.

A single bright yellow crystal only occurs, and it lies so deep in the specimen, between two mammillations of prehnite, that its form cannot be deciphered.

I was induced by the urgent solicitations of a local collector, to whom I mentioned the find, to refrain for a time from announcing it. His argument was that the mineral collectors of the neighbourhood should have the earliest chance of being supplied.

As I have myself fruitlessly visited the quarry since, and as even the occurrence of the ordinary zeolites is only very occasional therein, I conclude that time must elapse before more crystals are turned out.
Apatite from a New Locality in Eastern Cornwall
Authors: Solly R. H.
Published: December 2006

In the last Number of the Society's Journal I described some crystals of apatite (francolite variety) from St. Just district of Western Cornwall; I have now to bring to the notice of the members some very fine beautiful crystals of this same mineral which I have received from Mr. Henson.

In point of beauty and lustre they far surpass any of the apatites that have yet been found in England.

The crystals are in the form of hexagonal prisms, doubly terminated with basal planes and narrow pyramid planes; colour pale bluish green, translucent with strong vitreous lustre.

They vary in size from a pin's head to half-an-inch across.
Celestine from a New Locality in Gloucestershire
Authors: Solly R. H.
Published: December 2006

The great similarity which exists in the crystallographie and optical constants, cleavage, and absence of twinning in the isomorphous rhombic sulphates is especially marked in Barytes and Celestine, but though the combination of forms is sometimes the same, yet up to the present time a marked individuality has bees perceived in Celestine crystals which has made it easy to recognise the one mineral from the other.

The crystals of Celestine from near Bristol in the red marl, those associated with sulphur from Sicily, or the large flat more or less bluish tabular crystals from Strontian Island, Lake Erie, are varieties which are seldom if ever mistaken for Barytes.
Note on the presence of Lead in Calcites from the Leadhills District
Authors: Thomson J. Stuart
Published: December 2006

The not unfrequent occurrence of the variety of Calcite, containing Carbonate of Lead and known as "Plumbo-calcite," at the Leadhills district, suggested that an examination of some of the ordinary Calcites from this locality, for Lead, might be of interest. The specimens for this examination were most kindly put at my disposal by Dr. Wilson. All of them were ordinary Calcites, none consisting of the recognised Plumbo-calcite.
Note on some Specimens of Glaucophane-Rock from the Ile de Groix
Authors: Bonney T. G.
Published: December 2006

In my description of a Glaucophane-eclogite from the val d' Aoste, I alluded to the occurrence of a rather similar rock in the Ile de Groix (off the south coast of Brittany) in the following words:—" In the Ile de Groix the glaueophane occurs in no great abundance, with greenish mica, epidote, garnet, hornblende, and but little quartz." My knowledge of the rock, as then stated, was from one or two specimens only; but in the autumn of 1886 I paid a short visit to the Ile de Groix in order to see the rock in the field. I then found that in the above phrase I had unwittingly done an injustice to this locality for glaucophane, for I obtained specimens in which that mineral is even more abundant and almost as well developed as in the rock from the Val d' Aoste. On this account, and as the locality is rarely visited, I venture to think that a few notes may be interesting to the Society, although the rock has been already excellently discussed by Dr. Charles Barrois, to whom I am much indebted for information about this and other interesting localities in Brittany.
Notes on the Microscopical Structure of some Eruptive Rocks from Armenia and the Caucasus
Authors: Gylling Hjalmar
Published: December 2006

In 1881-1882 Dr. A. Brotherus and his brother, A. H. Brotherus, made a botanical tour in Armenia and the Caucasus; the younger gentleman collected a few specimens of rocks met with during their journey, which, on his return, he kindly left to be examined by me.

This material consisted of later eruptive rocks; it was scanty, but as it was obtained in places from which we have no earlier information of a similar character, I have not thought it uncalled for to make in the following lines a slight contribution to our knowledge of the geognosy of the regions in question.

The microscopical analysis of rocks from the Caucasus made by Tsehermak, Lagorio, and Möhl relate in part to the identical rocks that I shall describe, but the localities are different.
On Granite containing Andalusite from the Cheesewring, Cornwall
Authors: Teall J. J. H.
Published: December 2006

The granite of the Cheesewring Quarry is coarse grained and grey in colour. It is essentially composed of white felspar, quartz and two micas. Tourmaline occurs sparingly. The dominant felspar is orthoclase, frequently twinned on the Carlsbad plan. Crystalline form is not well developed. Under the microscope the individual grains do not, as a rule, give detinite extinction. Different portions extinguish at slightly different angles. The arrangement of the different portions is often very irregular; sometimes, however, it gives rise to a striped structure, under crossed nieols, suggestive of micro-perthite ; but in no case has a perfectly definite intergrowth of plagioclase and orthoelase been observed. Examined by Szabo's method the orthoclase is seen to be fairly rich in soda. A well striated plagioclase occurs in the rock, but is present in very small quantity. When it does occur it is often seen to be idiomorphic with respect to quartz.
Note on Francolite
Authors: Butler F. H.
Published: December 2006

Some little confusion having apparently arisen with respect to the characters of certain Cornish apatites, it may be well in the interests of scientific exactitude to point out the following facts. —In a series of specimens of Franeolite from Fowey Consols one may observe every gradation of form betwixt long and coarsely striated hexagonal prisms and narrow-edged crystals of an almost lenticular shape. Similar to the latter in their small vertical measurement are the "thin hexagonal plates" which have been enumerated among the known varieties of Cornish apatite, and which are, indeed, indistinguishable in general characters from the recently described Francolite of Levant Mine, St. Just. The particular Francolite, however, which, obtained by Mr. Talling from Fowey Consols, was shown by Maskelyne and Flight to contain over 5 per cent. of calcium carbonate (Journ. Chem. Soc. Jan. 1871), must not be identified with any one of the three varieties just mentioned.
On Crystals of Cuprite and Cerussite resulting from the slow alteration of buried coins
Authors: Fletcher L.
Published: December 2006

The coins referred to in this paper were received through Professor J. W. Judd, F.R.S., to whom they had been sent by Mr. George W. Shrubsole, F.G.S., Honorary Curator of the Museum belonging to the Chester Society of Natural Science.

According to Mr. Shrubsole the Roman coins of Chester are generally found in soil consisting more or less of disintegrated red sandstone and clay : the coins of the find now under consideration must have been buried for fifteen centuries, for such as have been deciphered belong to what is called the Roman Third Brass, and range from Philippus, A.D. 244, to Constantine, A.D. 887. Mr. Shrubsole further remarks that crystals are not found to result from the alteration of isolated coins ; when met with they line cavities between adjacent coins of a pile.
On the Crystalline Form of Creatine
Authors: Fletcher L.
Published: December 2006

Some small crystals of a substance, supposed at the time to be an allotropic modification of Creatinine (C4H7N3O), were submitted to me for crystallographic determination. The crystals of which the angles were to be measured were thin elongated plates nearly of an inch long, of an inch broad, and of an inch thick.
On a Variety of Glaucophane from the Val Chisone (Cottian Alps)
Authors: Bonney T. G.
Published: December 2006

As I was descending the Val Chisone from the Col de Sestriéres last summer, my eye was attracted by the peculiar colour of an erratic, which was lying on the hillside very near the road. The violet-blue tint, generally indicating the presence of giaucophane, was perceptible, especially in certain lights, but, as it was much less strongly marked than in rocks in which I had previously observed the mineral, I felt doubtful. However, I secured a good specimen, and now find on microscopic examination that glaucophane is present, though it is a pale coloured variety, differing from those which I have hitherto examined.

The block was a fairly large one, perhaps more than a square yard in area, and a couple of feet thick. I did not, however, take measurements, as the exact size was unimportant.
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.
Note on the Occurrence of Celestite containing nearly fourteen per cent. of Free Sulphur
Authors: Johnston-Lavis H. J.
Published: December 2006

The mechanical inclusion of foreign substances in crystals during their formation is of such common occurrence that it might appear superfluous to record further examples, were it not that the present ease is a somewhat unique one. All mineralogists are acquainted with the inclusion of sand and clay in selenite, celestite, and calcite, of which the Fontainebleau limestone is a striking example. Delesse found the crystals of calcite from that locality to contain 57 per cent. of sand, and to have a sp. gr. of 2·84, whilst the sp. gr. of pure calcite is given by Beudant as 2·721 to 2·723, which demonstrates that the inclusion of the heavier quartz grains raises the sp. gr. of the impure crystals.
Notes on Hornblende as a Rock-forming Mineral
Authors: Harker Alfred
Published: December 2006

The part played by hornblende (i.e. the monoclinie amphiboles) in the constitution of rocks, and the relation of that mineral to angite (including all the monoclinlc pyroxenes), are subjects which, in recent years, have occupied much attention. It has been recognised that the early notions of paragenesis cannot be applied, without many reservations, to rock-forming minerals. Some petrologists have gone so far as to suppose that augite and hornblende "are two different crystallographic forms of essentially the same molecule, of which the former is most stable at high, the latter at ordinary temperatures." If this view receives any extensive confirmation, the well-known conversion of angite into hornblende must be regarded as a purely paramorphic change due to altered conditions.
On a peculiar variety of Hornblende from Mynydd Mawr, Carnarvonshire
Authors: Bonney T. G.
Published: December 2006

Mynydd Mawr is a conspicuous hill with a craggy face towards the north, and a well-marked corrie (Cwm Du) on that side. It lies to the south-east of Moel Tryfan and the west of Llyn Cwellyn (Carnarvonshire). On the Geological Survey map it is represented as a somewhat rounded oblong patch of felstone, about 1⅜ mile from east to west, and a mile, or a little more, from north to south, intrusive in Lower Silurian (Ordovieian) rocks, which are probably Arenig. I passed some years since to the north of the above-named face, and collected specimens from erratics which were plentifully strewn over the lower land. On microscopic examination I found them to contain a very puzzling and remarkable mineral which I have long intended to describe, but kept deferring this in hope of being able to revisit the place to obtain more specimens for examination, and by taking these from rock in situ, to prevent any question arising as to the true source of the rock.
Note on a Picrite from the Liskeard District
Authors: Bonney T. G.
Published: December 2006

Specimens of this rock were presented a short time since to the British Museum by the Earl of St. Germans, and Mr. T. Davies, knowing my interest in pierites and peridotites, kindly requested me to examine them and communicate the results to the Mineralogical Society. The rock occurs, as I am informed, in boulders between Menheniot and St. Germans. The picrite of the Clicker Tor, near the former place, is well known and has been more than once described, but, as all specimens which I have seen from that locality are very different, macroscopically and microscopically, from those now sent to me, it may be well to put on record a description of the latter, which, after the excellent summary of the mineral character of picrites given in Mr. Teall's British Petrography, need not be lengthy.
Notes on some Minerals from the Lizard
Authors: Teall J. J. H.
Published: December 2006

This mineral is found as a constituent of a variety of gabbro occurring on the shore at the village of Coverak, Cornwall. The rock is an aggregate of allotriomorphic grains of chrome-diopside, labradorite and olivine. The olivine is, in general, perfectly fresh, but it is traversed by a network of veins in which magnetite has been deposited. The whole of the iron-ore present in the rock occurs in these veins in the olivine ; so that in this, as in other respects, the rock bears a close resemblance to some of the gabbros described by Prof. Judd from the Western Isles of Scotland.
A Mangano-magnesian Magnetite
Authors: Chester Albert H.
Published: December 2006

A mineral from New Zealand, said to be chromic iron, presumably from its occurrence with serpentine, being found to contain no chromium, was analysed under my direction by Mr. F. J. Cairns with results given below. The mineral occurs both massive and crystallised in a light yellowish-green serpentine, with which it is so intimately mixed that it was found impossible to pick a specimen for analysis that was entirely pure, though as far as possible the distinct crystals were taken. These crystals are about one-fourth of an inch in diameter, and all noticed have the form of the rhombie dodecahedron. The specific gravity is 4·67, and the colour iron-black.
The Minerals of the Treshinish Islands
Authors: Heddle M. Forster
Published: December 2006

Through the cordial assistance and generous hospitality of Mr. Brown, of Dunipaee, formerly a member of the Mineralogical Society, I have lately been enabled to add very largely to the list of mineral localities in the Western Islands of Scotland.
On the large Porphyritic Crystals of Felspar in certain Basalts of the Isle of Mull
Authors: Holland Thomas H.
Published: December 2006

In the basaltic lavas of Iceland certain porphyritic crystals of unusually large dimensions, occur embedded in the matrix of the rock, and from an early date have received the notice of writers on the geology of that island. Amongst these authors might be mentioned :—Professor Forchhammer, Dr. F.A. Genth, M. A. Damour, Prof. Zirkel, M. P. Schirlitz, and M. R. Bréon.
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 Zinc Oxide from a Blast-furnace
Authors: Tudor Cundall J.
Published: December 2006

Crystallised, substance from a blast-furnace at Mostyn, in N. Wales, having been brought under my notice by Mr. Heywood, of St. Mellons, it was thought worth while to subject it to a careful examination. The largest of the crystals was about 6 mm. long and 2 mm. in diameter. They were translucent, varying in eolour from almost colourless to honey-yellow, and were arranged in tufts on what seemed to be altered firebrick. They yielded a pale yellow powder of which the specific gravity was found to be 5·605.
On Zinc Sulphide replacing Stibnite and Orpiment; Analyses of Stephanite and Polybasite
Authors: Prior G. T.
Published: December 2006

In a paper in Zts. f. Kryst. IX. 186, Professor Laspeyres states that the yellow enerustation uponFelsSbanya stibnite is not ecrvantite, but a sulphide of zinc, which he determines to be wurtzite, chiefly on the optical ground that a black interference cross was observed between crossed nicols, for the chemical proof based on the solubility in cold concentrated hydrochloric acid can hardly be regarded as very conclusive, considering the fact that he had no true wurtzite with which to make the comparison, but only so-called schalenblende, spiauterite, etc. On this account it seemed desirable to test the solubility of wurtzite in HCl, and accordingly a series of experiments as to the comparative solubility of wurtzite, spiauterite, voltzite and different varieties of blende was made by treating small fragments with cold concentrated HCl, (as was done by Professor Laspeyres) in small tubes, in the mouth of which strips of lead acetate paper were inserted.
The Meteoric Iron of Tucson
Authors: Flecher L.
Published: December 2006

Two large masses of meteoric iron, which have been removed from Tucson, are now preserved, the one at Washington, the other at San Francisco. According to Lippincott's Gazetteers Tucson is "a posttown, capital of Pima County, Arizona, U.S.A., on the Rio Santa Cruz, and on the Southern Pacific Railroad, about 250 miles east of Yuma. It was founded in the year 1560 by the Jesuits. It contains a church, the Institute of St. Joseph, two free schools, a bank, a newspaper office, a court-house, a United States depository, many stores, and two flour mills. The population in 1880 was 7,007."
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.
A Visit to the Calcite Quarry in Iceland
Authors: Hoskyns-Abrahall J. L.
Published: December 2006

In the summer and autumn of last year I paid a visit to Iceland, and I as I had been told by my friend, Mr. Madan, that the difficulty of obtaining large pieces of clear calcspar for optical purposes had been exciting some curiosity as to the state of the quarry itself, and as the peculiarity of the deposit made it an object of interest, I thought it worth while to force Eskirjördhr into my route. The narrow fjords of Sudhrmúla Sysla, of which Reydhartjödhr, the largest, bisects the East coast of Iceland, are cut out of an immense plateau, formed of horizontal sheets of Volcanic rock—chiefly trachyte—between three and four thousand feet high. This has been subsequently eroded into sharp bare ridges with immense cliffs or steep slopes falling from them, parted by torrent valleys and fjords ; the greater part of the district not reaching the present snow-line.
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 Occurrences of Riebeckite in Britain
Authors: Cole Grenville A. J.
Published: December 2006

In the summer of 1890, in the company of Mr. L. W. Fulcher, I again visited Mynydd Mawr, on the west of the Snowdon area, in the hope of obtaining specimens of Riebeckite larger than those on which Mr. Harker and Professor Bonney based their observations in 1888, when they independently pointed out the occurrence of this mineral for the first time in the British Isles. Previous traverses of the dome-shaped mass had shown how uniform in structure and how minutely crystalline the rock of Mynydd Mawr was over all its surface; we accordingly examined the columnar cliffs on the north and west, paying especial attention to the great western hollow, where denudation allows one to stand almost in the centre of the intrusive neck. But even here we were somewhat disappoinied, and our specimens are only slightly coarser in grain than those studied with such striking results by Professor Bonney.
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.
Danalite from Cornwall
Authors: Miers H. A. , Prior G. T.
Published: December 2006

The specimen which is the subject of the present note consists of a group of large rude, reddish crystals of tetrahedral aspect, which in colour, lustre, and general appearance, resemble garnet; they were formerly supposed to be garnet pseudomorphous after some tetrahedral mineral, and the original mineral was presumed to have been fablerz, on account of the size of the crystals, which measure as much as 3 to 5 centimetres across.