bluuebunny/crossref_metadata_2025 huggingface dataset:
IV. On a peculiar pasty form of Silica, from a cavity in Gold-bearing Quartz
Authors: French A.
Published: December 2006

The alluvium over an area of about 50 square miles around Lead-hills in Lanarkshire, is auriferous. In many places the precious metal may be rendered visible after fifteen or twenty minutes washing with the primitive wooden trough employed by the local gold-seekers. Frequently nuggets have been found weighing from one to four or five pennyweights, and these are often either contained in pieces of loose quartz, or have quartz fragments attached to them; there are therefore good reasons to believe that the gold found in the red stratum of clay lying immediately above the rock has been derived from the numerous quartz veins which traverse the district.

The author was one day searching, along with some friends, for gold quartz in situ, and while examining a vein which crosses a gulch in the hills, called the “Gold Scars,” found cavities in the quartz filled with a peculiar pasty substance, which appeared at first sight like minute scales of silver, which had been precipitated from a solution. Our first impression was that it was silver, but its behaviour in water soon cleared away the delusion; it rendered the water exceedingly turbid and white, and the suspended matter was a long time in settling.
IX. Preliminary Notice of substances which may prove to be New Minerals
Authors: Heddle
Published: December 2006

I give this name to a substance which may be regarded as of the nature of a hydrated magnesian felspar.

It was found by Mr. Dudgeon and myself in granular limestone, about one third of a mile above and north-east of the hamlet of Balvraid; this hamlet is situated six miles up the Glen Beg of Glen Elg, Inverness-shire.

Only a single large mass containing the mineral was found. In this mass it was associated with blue necronite (orthoclase of limestones), Biotite, and a hydrated labradorite.

Its colour is purplish brown of a pale cast; its structure is crystalline granular, it may be called saccharoid; its hardness is 6; its specific gravity from 2·905 to 2·908
XI. On the Geognosy and Mineralogy of Scotland
Authors: Heddle
Published: December 2006

Every writer has his moods. It may be thought that the present writer was cynical and severe in his remarks on the geognostic features of Caithness. With a view to remove any such impression, Dr. Maculloch's opinion of that country is quoted ; specially in order that it may be used as a foil to what has to be said concerning the geognosy of Sutherland.

Hear then Macculloch. “On entering into Caithness all the pleasures of travelling are gone and past, for an uglier country from one end to the other would not easily be found. In the usual sweeping manner of those who love to generalise, like Humboldt, it is level, or, at least, not hilly, without trees, without enclosures, as black and as flat as Bagshot Heath ; as flat as a pancake ! Nature has provided no monuments, and has refused to be its poet.
XIII. On Substances which may prove to be New Minerals
Authors: Heddle
Published: December 2006

My notice of this must be considered preliminary in every way. The discovery of “the beautiful carnelian marble of Tyree” has been in a late paper credited to Dr. Walker.

For some years after its discovery, it was used, or attempted to be used for mantle-pieces, and other internal decoration.

Partly on account of the minuteness of its pattern unfitting it for this purpose, and partly on account of the small quantity sent into the market, it, however, seems never to have found its way into general favour.

We find Dr. Macculloch lamenting the wasteful method of working adopted in the quarry,—the wholesale shattering of its mass by the excessive use of “Mines.”
XIV. On Crystallized Olivine from Slag
Authors: Trechmann Charles O.
Published: December 2006

I have recently measured one of the crystals of the slag described by by Mr. A. E. Arnold, in vol. III, p. 114 of the Magazine. Observed forms :—

The angles are therefore almost identical with those derived by Miller (Trans. Phil. Soc., Cambridge, III; Brooke and Miller, Mireralogy, 1852, P. 319) from crystals found in refinery cinder, and the slags of copper furnaces, &c, —having the composition of Fayalite, viz.—2 FeO, SiO2.
The Geognosy and Mineralogy of Scotland
Authors: Heddle
Published: December 2006

While agreeing with those writers who affirm that many of the members of this series are of the nature of schists, —sometimes almost flaggy schists, still, even when examined throughout their multitudinous varieties, it has to be affirmed that they are all gneissic schists; and, however fissile some of. these members may be, this is far from a sumcient reason for attempting to dispense with a time-honoured appellation;—one moreover which is more fittingly applied to them, than to the somewhat more generally hornblendic rock to which alone it has been proposed to confine its use.
IV.―On some Artificial Forms of Silica, illustrative of the structure of Agates, Chalcedonies, &c
Authors: I'Anson J. , Pankhurst E. A.
Published: December 2006

It is a common chemical fact, that when a solution containing an alkaline silicate is acted upon by any reagent capable of separating the silica from the base, the silica is in the majority of cases thrown down in a solid form. The fact of this reaction is all that, as a rule, the chemist would look at: but in addition to the mere chemical fact of the precipitation of the silica, another most important element from the mineralogist's point of view is that of the form in which this precipitate of solid matter appears. This form naturally varies with the various conditions of the experiment, and it is by the study of these varying forms that the authors have sought to elucidate, experimentally , the wondrous and beautiful varieties of structure which are so familiar to us in the endless forms of silica occurring in nature.
Description of the Geological Map of Sutherland
Authors: Heddle
Published: December 2006

It was with considerable reluctance that I felt myself compelled to discard the system of coloration adopted in the Geological Survey Maps; and rids I did only after the strongly expressed opinion of several geologists.

It was not that I have any very intense desire to colour rocks after their natural tints, but I have an aversion to adopting a colour suite which departs markedly therefrom; or one which is in discordance instead of harmony therewith. One friend, a man of great scientific discretion, and himself an artist, writes me that when he looks at a recently published geological Map of Scotland, with its grey Torridon and its red Laurentian, he does not know whether he is standing on his head or his heels.
On a New Mineral Locality
Authors: Heddle
Published: December 2006

It is but seldom, at least in the experience of the writer, that a new mineral locality is now found in this country. By a mineral locality I mean, not a spot where one or two specimens may be gathered, but one at which there is a supply sufficient to entitle it to be recorded as a spot likely to be productive to a sequence of gleaners; and such as holds out hopes of its yielding specimens of more than average excellence.
Analyses of a Variety of Saponite
Authors: Dobbie J. J.
Published: December 2006

The variety of saponite described in the following note was first obtained by Mr. Waiter Burns, of the Geological Society of Glasgow, from a quarry in the Cathkin Hills, about three miles S.S.E. of Glasgow, The quarry is hewn out of dark-coloured dolerite, rich in olivine, which restg on beds of felspathic ash. The dolerite has in places been converted into a green-coloured fibrous variety of saponite (Boulingite), which is found in veins of from 2 to 8 inches in thickness. This variety has been analysed by Prof. Heddle, as well as by Mr. G. Wallace Young and Mr. G. B. Hannay.
A Portable Blowpipe Lamp
Authors: Thompson J. Stuart
Published: December 2006

While making some experiments with a form of miner's lamp, which has recently been introduced for the purpose of burning soft paraffin wax in place of tallow, it occurred to me that this wax, which melts at about 38°C would be a very suitable fuel for a portable blowpipe lamp, being both cheap and cleanly. Having thus got a suitable fuel, the next step was to devise a lamp to burn it, and afar one or two trials the form shown in the annexed sketches was adopted.
On a Crystal of Apatite
Authors: Henson S.
Published: December 2006

The accompanying engraving represents an exceptionally fine group of crystals ofapatite, found in the Untersulzbachthal in Salzburg. The dimensions are those of the original, its colour is white with a delicate tint of mauve. This group is the finest of three of the most magnificent specimens yet found at this or any other locality, the largest one having been deposited in the national collection of minerals at South Kensington, while the third was unfortunately broken.
The Crystallography of Bournonite
Authors: Miers H. A.
Published: December 2006

The above table is a list of all publications which contain original crystallographic work, observations, or figures relating to Bournonite ; it omits the names of many other works which mention the mineral, but merely contain information compiled from earlier sources; and it refers only to such works as are concerned with the crystalline form. The complete history of the crystallography of Bournonite will therefore be found in the above publications. The most important and comprehensive of these is the monograph of Zirkel published in 1862 ; this paper contains a summary of the previous literature and the results of many new observations, together with a large number of new figures.
The Origin of the Andalusite-Schists of Aberdeenshire
Authors: Horne John
Published: December 2006

Perhaps the most difficult question in the science of Geology at present, is the explanation of the origin of the metamorphic crystalline rocks which occupy large areas on the surface of the globe. These rocks have been generally regarded as having undergone a vast amount of change in lithological character, to which the term metamorphism has been applied. By local or contact metamorphism is meant the transformation which has been effected in ordinary sedimentary strata by the intrusion of igneous rocks, the extent of which depends on the relative size of the intrusive mass.
Note on a New Mode of Occurrence of Garnet
Authors: Louis H.
Published: December 2006

Garnet is most commonly found in the form of separate crystals embedded in metamorphic rocks; occasionally, but comparatively rarely, in beds or veins. On a recent visit to the Pyrenees, in the Province of Catalonia, I found this mineral forming what appears to be a true dyke. I first noticed an outcrop of it in the steep banks of a brook, in one of the higher valleys of the main mountain chain. At this point it had the appearance of a vein, almost vertical and running nearly East and West ; the wall rock was a highly metamorphic schist, so that its stratigraphical relation to the garnet could not well be made out; however, the general strike of the strata in this district is about East and West.
Note on a Case of Replacement of Quartz by Fluor Spar
Authors: Bonney T. G.
Published: December 2006

This unusual substitution appears to have taken place in a rock found by Mr. R. N. Worth, F.G.S., on Trowlesworthy Tor. The specimen was a loose block, and the rock to which Mr. Worth has given the name of Trowlesworthite has not yet been discovered in situ. The rock consists of red felspar, fluor-spar, and tourmaline, associated with quartz, and its general character and microscopic structure are described in papers published in the Transactions of the Royal Geological Society of Cornwall, Vol. X. p. 177.
Notes on “Enargite” from Montana, U.S.A.
Authors: Semmons Wm.
Published: December 2006

The deleterious effects of small quantities of Arsenic when present in Copper are weI! known to all who are concerned with the working of thin latter metal, and the elimination thereof is consequently an object to which the copper smelter pays special care. Though a large number of minerals, some of which are of exceeding beauty, are found composed of Copper combined with Arsenic acid, the direct combinations, as Araenide and Sulph-Arsenide, are comparatively rare.
Analysis of an altered Siderite from Helton Beacon Lead Mine, near Appleby
Authors: Trechmann C. O.
Published: December 2006

It appeared of interest to determine the nature of the alteration which has changed the light greenish or brownish yellow siderite to the dark, almost perfectly black, glossy crystals so often seen on specimens from this neighbourhood.

The material, gathered from the heap of a mine, consisted of massive siderite, crystallised on its natural surfaces in the form of small curved primary rhombohedrons, and associated with quartz, pyrites, blende, and other minerals.
Connellite from Cornwall
Authors: Trechmann C. O.
Published: December 2006

The crystals are of a similar length, though often considerably thicker than those described by Prof. Maskelyne (Phil. Mag. Jan. 1868), and his general description applies to those under consideration.

They are, however, ill-adapted for measurement, as single perfect crystals are rare. As a rule several crystals are longitudinally attached to one another, with slight radial divergence, in such a manner that it becomes difficult or impossible to discriminate between the reflections of their minute faces.
On the chemical composition of some samples of graphite from Knock Aberdeenshire
Authors: Ivison Macadam W.
Published: December 2006

The proportion of actual carbon varies much in different samples. Some portions are stated to have analysed as high as 75 per cent., but, as will be noticed from the figures given below, the carbon may be much lower.
Further Notes on Enargite
Authors: Semmons W.
Published: December 2006

When I submitted my Paper on Enargite (Min. Mag. Vol. vi. p. 49) to this Society, I was unable to give the exact locality of the mineral. As the territory of Montana embraces a considerable extent of land, I was therefore desirous of ascertaining the position of the mines yielding the ore.

Having during the past summer had the opportunity of visiting the locality, I am now able to give some further particulars.
Address to the Mineralogical Society
Authors: Bonney T. G.
Published: December 2006

At the conclusion of my term of office it is a great pleasure to me to be able to congratulate the Society on the condition of its finances. This, three years since, caused some of us no little anxiety ; now, thanks to the efficient management of our Honorary Secretary, we can look forward to the future with confidence.
Orthoclase from Kilima-njaro, and Adularia from Switzerland
Authors: Miers H. A.
Published: December 2006

Professor Bonney has described, in the British Association Report for 1885, the rock specimens brought from Kilima-njaro by Mr. H. Johnston, and has called attention to the peculiar form of the felspar crystals which are porphyritieally developed in a rock referred by him to augite-andesite. It is at his suggestion that a more detailed account of these crystals is here attempted.

They are of a brown to yellowish-brown colour, full of cavities, and considerably weathered, and are so much rounded that it is impossible to determine their nature with certainty by means of the hand goniometer. They sometimes attain a length of 85 mm.
On the Nomenclature of the Hydrocarbon Compounds, with a suggestion for a new classification
Authors: Taylor Andrew
Published: December 2006

Since many of the minerals grouped as hydrocarbon compounds in Dana's Mineralogy have become extensively exploited for their commercial uses, allied questions in chemical geology and in their classification have bulked largely in scientific discussion. Thus their place as rocks or minerals in petrology has been mooted; for it is difficult to make out definite chemical composition or crystallographic form in many of the materials of the group now used for heating, lighting or paving. Notably the question, What is coal ? has not been authoritatively removed from the range of scientific controversy―though the supply of the mineral which occasioned the great trial Gillespie v. Russel, nearly thirty years ago, was, until last year, considered exhausted. Diligently bored for to its exact position inthe Scottish carboniferous series of rocks, no trace of it has been found except in its limited basin of four miles area or so around Torbanehill, Linlithgowshire.
Anglesite from Portugal
Authors: Solly R. H.
Published: December 2006

These crystals of anglesite were given to me by Dr. Gadow, the Strickland Curator to the University of Cambridge, who obtained them while on a zoological expedition to Portugal.

They were given to him by the agents at the San Domingos copper mines near the Guadiana river in the province of Algarve, South Portugal, as crystals strange and unknown to them.

The only Portuguese localities recorded at present for anglesite are far north of these mines.

The San Domingos mines are worked in a portion of the great metallic lode or bed which stretches from the S.W. of Portugal, across the southern portion of Spain, in the province of Huelva, in an E.S.E. direction, and appearing again in a similar manner and direction on the other side of the Mediterranean in Algeria. The age of the surrounding strata is a matter of dispute.
On Plattnerite
Authors: Kinch Edward
Published: December 2006

This mineral, lead dioxide, does not seem to have been examined since it was first noticed by Breithaupt and Plattner in 1837 (Journ. pr. Chem. x. 508). This specimen, named "Schwerbleierz," is said to be probably from Leadhills, and the mineral is called, in the manuals of Dana and others, a doubtful species. It was named Plattnerite by Haidinger and subsequent authors.

A short time ago my friend Mr. Thos. Davies, F.G.S., of the British Museum, asked me to analyse a mineral from Leadhills, Lanarkshire, which he had had in his possession for some years, but the examination of which he had, from various causes, frequently postponed. On examination it was found to be lead dioxide—Plattnerite.
Note on Schorlaceous Rocks from near St. Austell
Authors: Butler F. H.
Published: December 2006

Certain specimens of rock lately obtained by me from the "Single Rose" Clay Work, near St. Austell, Cornwall, examples of which are now submitted to the Society, illustrate well the processes by which, in some instances at least, granite has been transformed into an aggregate of quartz and schorl.

A comparison of the chemical composition of orthoclase from Roche with that of kaolin from the neighbouring district of St. Stephen's shows that in the passage of felspar into China clay there is approximately a loss of 26 per cent. SiO2 and a gain of 19 per cent. Al2O3 and 12 per cent. H2O.
On the Relations between the Solution-planes of Crystals and those of Secondary Twinning; and on the Mode of Development of Negative Crystals along the Former. A Contribution to the Theory of Schillerization
Authors: Judd John W.
Published: December 2006

In the case of many common rock-forming minerals—the felspars, the pyroxenes, the olivines and the micas—it has been shown that the crystals which have existed in rock-masses at great depths exhibit constant and characteristic differences from the crystals of the same mineral, in rocks of identical composition, which have been formed at the surface. It has been proved, moreover, that these differences become mere and more pronounced in proportion to the distance from the surface at which these rocks have originally existed.

Although some of these peculiarities of the crystals of deep-seated rockmasses can be satisfactorily accounted for by the conditions of pressure and slow growth under which they were originally formed, yet there are others—and these by no means the least striking of them, such as the continuous bands of fluid-enclosures, the avanturine structure and schiller, and the chatoyant phenomena—which are clearly not original, but are due to secondary actions.
On a Meteoric Iron seen to fall in the District of Nejed, Central Arabia, in the Year 1863
Authors: Fletcher L.
Published: December 2006

In 1885 a trustworthy Persian agent, through whom various antique objects had been already acquired for the British Museum, offered for sale to its authorities a so-called thunderbolt, weighing 131 lbs. (59.4 kilograms), and submitted at the same time the following translation of a Persian letter from his Excellency Hajee Ahmed Khane Sarteep, Ex-Governor- General of Bunder Abbas, Persian Gulf, and Grand Vizier of Muscat:—
On the Nature and Origin of Clays: The Composition of Kaolinite
Authors: Collins J. H.
Published: December 2006

The clays appear under many widely different aspects, and from one point of view must be studied as rocks. There are rock-masses alike of clay and of serpentine, both the result of important metamorphic processes. The basis, however, of most—probably of all—clays appears to be a substance of definite composition and well-marked characters, as much entitled to specific mineral rank as allophane or serpentine, or perhaps opal. In this paper I propose to consider clay as a rock and as a mineral.
On the Development of a Lamellar Structure in Quartz-crystals by Mechanical means
Authors: Judd John W.
Published: December 2006

As long ago as 1816, Brewster showed that many crystals have a lamellar structure developed in them by pressure, and his observations became the starting point of a long series of very valuable researches. Reuseh proposed that the planes along which such structures are developed by mechanical means should be called "Gleitflächen" (gliding-planes), and he, Pfaff, and other mineralogists have investigated a number of curious cases of the kind. Baumhauer in 1879 showed that the lamellar structure could be brought into existence, in the ease of calcite, by simply inserting s knife-blade in a definite direction into cleavage fragments of the mineral, and his observations were confirmed in the following year by Brezina.
On Kaolinite
Authors: Dick Allan
Published: December 2006

I propose to add one more account to those which have already been published of this mineral. It is described as a rhombie mineral in Dana's Mineralogy and other standard works. Latterly it has been described by Reusch as an anorthic mineral, from National Belie Mine, Red Mountain, Colorado, in the Jahrbuch für Mineralogie, 1887, Bd. II. Now I describe it as monoclinic, principally from a study of that variety of it which occurs in Anglesey, of which an account was published by Dr. Percy in 1875 in his Metallurgy, Vol. "Fuel."
Contributions to the Study of Pyrargyrite and Proustite
Authors: Miers H. A.
Published: December 2006

The labour of tracing the history of the Red Silver Ores, of collating the literature, and of tabulating the crystalline forms previously observed, has been, to a large extent, rendered unnecessary by the memoir published by E. Rethwisch (Neues Jahrbuch für Mineraloqie, Beilage Band iv. (1886), pp. 31-109), under the title "Beiträge zur mineralogischen und chemischen Kenntniss des Rothgültigerzes."
On Dufrenite from Cornwall
Authors: Kinch Edward
Published: December 2006

Some of the published analyses of specimens of Dufrenite have afforded results not in good accord with the chemical formula 2Fe2O3, P2O5, 3H2O, usually ascribed to that species.

Moreover, since analyses of a crystallised Dufrenite from Cornwall gave results showing a higher ratio of acid to base than demanded by the above formula, a re-examination of the ordinary botryoidal variety of the mineral seemed desirable.
On the Zeolites of Rye Water, Ayrshire
Authors: Heddle M. Forster
Published: December 2006

The first volume of the Transactions of the Geological Society of Glasgow contains the following notice of Zeolites as occurring in the banks of the Rye Water:—"About one-and-a-quarter miles below Howrat Toll-bar, white and red stilbite occur, small white prehnites, with fine pellucid quartz approaching to hyalite, and calcite."
Elaterite: a Mineral-Tar in Old Red Sandstone, Ross-Shire
Authors: Morrison Wm.
Published: December 2006

This mineral tar, which, from its elasticity, though somewhat weak, resembles elaterite, is found at the Craig Well, near Dingwall.

It is an intensely black, lustrous, sticky substance, of the consistency of tar, and from its being associated with albertite it may be looked upon as a variety of that asphalt.
Analyses of Various Mineral Substances
Authors: Macadam Ivison
Published: December 2006

The samples analysed came from the bottom of a small loch. No. 1 was of a yellow-gray eolour, even in texture, and readily broken down between the fingers.

No. 2 was distinctly red, and marked with dark spots. It broke down readily, and was more dense than No. 1.

No. 3 sample was red in colour, with dark brown and red particles throughout the mass.
The Renaissance of British Mineralogy
Authors: Fletcher L.
Published: December 2006

It is my unpleasant duty this evening to retire from the honourab!e position in which I was placed by the members of the Mineralogical Society three years ago. Before doing so I would say a few words on a subject which has demanded grave consideration from myself, and doubtless also from my predecessors in the Chair : namely, as to whether any formal address should be delivered by your President during his term of office.
Calcites from the Neighbourhood of Egremont, Cumberland
Authors: Miers H. A.
Published: December 2006

A Remarkable series of crystallised calcites from Cumberland which have been found during the present year deserve description, both on account of their size and beauty, and also by reason of their peculiar form.

The crystals, although obtained from a small area, exhibit great variety of habit and appearance, and fall naturally into the seven groups which are described below. Of these the most remarkable consists of a series of magnificent heart-shaped twins, somewhat similar to the rare but well-known "butterfly twins" of Eyam, in Derbyshire; they result from the same mode of twinning as the latter, but are far larger and more beautiful than any of the Derbyshire twins, frequently measuring four inches in breadth. There are also crystals which exactly resemble the true butterfly twins of Eyam, and others which arc very similar to the rectangular twinned prisms of Wheal Wrey in Cornwall. A second and very rare twin law is also represented among these specimens, in which the rhombohedron, whose edges are truncated by the cleavage planes, acts as twin-plane.
A New Form of Microscope
Authors: Dick Allan
Published: December 2006

Many years ago I requested Mr. Swift to make for me a first-rate Binocular Petrological Microscope. The centering of the stage by screws was, I suppose, as good as it could be made. I found it unsatisfactory when using high powers on small crystals. A centering nose-piece answered no better. Only by the simultaneous rotation of the polariser and analyser by hand, little by little, could I keep the interference figures of small crystals in the field of view, or feel certain that the figures had not left it during rotation owing to the excentricity of the centering.
On the Meteorites which have been found in the Desert of Atacama and its neighbourhood
Authors: Fletcher L.
Published: December 2006

The immediate object of the present paper is to place on record the history and characters of several Atacama meteorites of which no description has yet been published; but incidentally it is convenient at the same time to consider the relationship of these masses to others from the same region, which either have been already described, or at least are stated to be preserved in one or more of the known Meteorite-Collections.
On the manner of occurrence of Beekite and its bearing upon the origin of Siliceous Beds of Palœozoic Age
Authors: McKenny Hughes T. M.
Published: December 2006

In the New Red breeciated conglomerate of the coast of South Devon there are numerous fragments of Devonian limestone, on the weathered exterior of some of which botryoidal and concentric chalcedony is commonly found. There does not seem to be anything in the nature of the material to call for a new name from a mineralogical point of view; but, as the ettalcedonic shells to be described are peculiar in their mode of occurrence and form and are locally called Beekites, and the mineral is commonly spoken of as Beekite, after Dr. Beck, Dean of Bristol, who first called attention to it, I will use the word where convenient.
On New Localities for Linarite, Caledonite and Epistilbite
Authors: Heddle
Published: December 2006

The following new localities for these t~ree rare minerals have lately come under my notice.

I was some time ago presented by George Moodie, Esq., formerly Surveyor-General to the Transvaal Government, with a specimen which he obtained himself from the lead mines at Marico Zeerut, near Potsehefstroom, in the Transvaal.

This specimen was part of a small druse which is lined with crystals in a corded arrangement. These crystals appear to me to be zinc carbonate.

Superimposed thereon there are crystals of both linarite and of caledonite, and also minute crystals of an emerald-green mineral which is unknown to me.

There being but one specimen, I do not desire to remove any of the last for testing.
On the Crystalline Form of Gyrolite
Authors: Heddle M. F.
Published: December 2006

In a late number of the Magazine I mentioned that I had obtained from several of the Treshinish Islands specimens of gyrolite, and that one of these carried crystals which seemed sufficiently perfect for the determination of the form of the mineral.

A careful examination of the specimen showed it to be somewhat fragile; and, as we know that the mineral is itseff excessively tender as well as soft, I thought it desirable that the most should be made of so unique an example.
Notes on Bowenite or Pseudo-Jade from Afghanistan
Authors: McMahon C. A.
Published: December 2006

A stone called sang-i-yashm in Persian, which has some points of resemblance to jade and is sometimes mistaken for it, is utilised at Bhera, in the Shahpur District of the Punjab, for the manufacture of dagger hilts, knife handles, caskets, amulets, and other articles. It is also found useful in mosaic work.

I am indebted to Mr. J. Wilson, B.C.S., Deputy Commissioner of the Shahpur District, for several specimens of the stone in the unworked state, and for information regarding its place of origin. Other specimens I obtained from my son Lieut. A. H. McMahon, Assistant Commissioner, Kohat.

The sang-i-yashm is a hard species of serpentine which seems to correspond very closely to that named bowenite, after Dr. Bowen, who, in 1822, published an analysis of a mineral from Smithfield, R.I., which up to that date had been called nephrite.
Twins of Marcasite in Regular Disposition Upon Cubes of Pyrites
Authors: Trechmann C. O.
Published: December 2006

The subject of this note derives interest less from its novelty than from the beautiful manner in which the intergrowth is exemplified in Nature. As Sadebeek has shown, the intergrowth of marcasite and pyrites takes place according to two laws.

(1) The vertical axis of marcasite is parallel with a principal axis of pyrites; one of the two other principal axes of the latter being parallel with the combination edge m (110) ∞P : c (001) 0P of the former ; or, in other words, the vertical and one lateral axis (ab) of marcasite coincide with two principal axes of pyrites.

(2) The vertical axis of marcasite is parallel with a principal axis of pyrites; the braehydiagonal axis is parallel with a diagonal axis of pyrites.
The Tetartohedrism of Ullmannite
Authors: Miers H. A.
Published: December 2006

Although all the modes of hemihedrism possible in the cubic system have been found to occur among minerals, no mineral l~elonging to that system has yet been proved to be tetartohedral like sodium chlorate, and the nitrates of barium, strontium and lead.

There has, however, been some evidence in favour of the tetartohedral character of Ullmannite since the examination of the crystals from Lölling in Carinthia, and those from Sarrabus in Sardinia. The former were found by Zepharovieh to be distinctly tetrahedral in form and habit, the latter were found by Klein to be distinctly pyritohedral. Zepharorich found the specific gravity of the Lölling Ullmannite to be 6·72, while Klein found that of the Sardinian crystals to be 6·803-6·883, and for this reason it was at first thought that the two occurrences might be different modifications of the antimono-sulphide of nickel; there was also considerable discrepancy between the two analyses.
On an Eclogite from Loch Duich
Authors: Teall J. J. H.
Published: December 2006

The existence in the British Isles of a rock essentially composed of garnet and omphacite, and answering therefore to Hauy's' definition of eclogite, does not appear to have been hitherto recorded.

The following description of such a rock from Totig Ferry, Loch Dutch, is therefore of some interest. The specimen was collected by the Director General, who informs me that he believes it to be a part of the Archæan gneiss which in the region of Loch Alsh and Loch Carron has been thrust bodily from the east over the Torridon sandstone.

The rock is of a dull green eolour, and contains numerous reddishbrown garnets. Under the microscope the principal constituents are seen to be garnet and omphacite—a pale green pyroxene without any definite crystalline form. Green hornblende, plagioclase, rutile, ironores, quartz, and epidote occur as accessories.
On a Micro-granite containing Riebeckite from Ailsa Craig
Authors: Teall J. J. H.
Published: December 2006

Riebeckite was first described by Sauer in 1888. The type-mineral occurs in granite from Socotra collected by Dr. E. Riebeck.

In the same year Harker identified the peculiar blue hornblende occurring in the quartz-porphyry of Mynydd Mawr with the mineral described by Sauer, and in the following year two fresh localities were given for this mineral by Le Verrier and Lacroix. The last mentioned observer has also shown that croeldolite must be referred to the same group of hornblendes.

The object of this communication is to place on record the occurrence of riebeckite in the so-called syenite of Ailsa Craig, the small island which stands at the entrance to the Firth of Clyde.
(1.) Tysonite and Bastnäsite; (2.) Meteoric Iron from Indian Valley Township, Virginia; (3.) Anatase; (4.) Sapphire
Authors: Kunz Geo. F.
Published: December 2006

About two years ago Mr. T. A. Herstand of Mainton Springs, Colorado, made a remarkable find of tysonite and bastnäsite at Crystal Park, near Malnten Springs, Colorado. The entire find consisted of one crystalline cleavable mass of tysonlte, covered with bastnäsite, weighing in all fully six kilograms. It was found in a coarsely crystalline granite, and no other deposit has been discovered subsequently, although considerable search has been made by various prospectors. Up to the time of this find all the tysonite discovered in Colorado has not amounted to more than 50 grams.

The tysonite was Principally of a rich cinnamon-brown colour with a perfect basal cleavage, and frequently contained patches from one to three cm. in diameter which were entirely transparent.
Minerals from the Apatite-bearing Veins at Noerestad near Risör on the S.E. Coast of Norway
Authors: Solly R. H.
Published: December 2006

The minerals described in this paper were obtained by Mr. Arthur L. Collins last summer, and their mode of occurrence is explained in the accompanying note by him. My description will deal in detail with their crystallographic characters.
Note on Crystals of Manganite from Harzgerode
Authors: Rutley Frank
Published: December 2006

On examining a specimen of manganite from Harzgerode, consisting of iron-black crystals of apparently long-prismatic habit, it was found that they were, in most instances, composed of many individual crystals, the latter ranging from about two to four millimetres in length. As they seem to differ in habit, so far as I know, from the crystals of manganite hitherto described and figured, a short account of them, pending more careful investigation and measurement, may be of interest.
Orpiment
Authors: Miers H. A.
Published: December 2006

The crystalline form of orpiment was first determined by Mohs (Grundriss der Mineralogie (1824), 2, 613).

His measurements, which he is careful to state were only approximate, gave an angle of 79°20' for the prism, and 83°7' for the brachydome; the plane of perfect cleavage being taken as the macropinakoid, and the crystals being referred to the orthorhombic system.
Additional Note on the Lamellar Structure of Quartz-Crystals, and the methods by which it is developed
Authors: Judd John W.
Published: December 2006

In a former communication to this Society, I have demonstrated that quartz must now be added to the long list of minerals in which a lamellar structure can be set up by mechanical stresses. In that paper, a crystal of smoky quartz was described in which well marked lamellæ could be detected; the relations of these lamellæ to the parts of the crystal which had suffered mechanical deformation and crushing are such as to leave no possibility of doubt that the lamellar structure is not an original but a secondary one; while it is equally clear that the structure has been developed by the action of mechanical forces upon the crystal.
On Geikielite, a New Mineral from Ceylon
Authors: Dick A.
Published: December 2006

The mineral which forms the subject of this communication came from the gem mines of Rakwana, Ceylon, and was brought to England by Mr. Joseph Baddeley, who, while superintending operations there, had formed a collection representative, it was believed, of almost every kind of pebble to be found at the works. This collection Mr. Baddeley, on his return home, submitted to Mr. Pringle at the Museum of Practical Geology, London. In looking, from time to time, over the collection, Mr. Pringle had occasion to take the specific gravity of some of the specimens. Amongst those so tested were certain pebbles the sp. g. of which was found to be about 3.98. This resuIt, combined with their other physical characters, having rendered it impossible for Mr. Pringle to assign them to spinel, ilmenite, or other species with which he could compare them, he handed the pebbles over to me for chemical analysis.
Xanthoconite and Rittingerite, with remarks on the Red Silvers
Authors: Miers H. A.
Published: December 2006

The name xanthoconite was given by Breithaupt (1) to a mineral which he found in 1840 associated with proustite upon an old ore-specimen in the collection of the Berg-Akademie at Freiberg. He describes it as occurring in reniform masses with a surface consisting of microscopic crystals, but with a crystalline granular interior.
On a discovery of “Oriental Ruby” and “Margarite” in the Province of Westland, New Zealand
Authors: Ulrich G. H. F.
Published: December 2006

In the early part of this year Mr. W Goodlet, laboratory assistant to Prof. Black, of the Dunedin University, submitted to me for examination a mineral specimen which he had brought from a journey of inspection of the gold fields of the West Coast, Middle Island. It had, so he told me, been broken from a boulder, about 40 lbs. in weight, which was found in the gold drift of a claim at Back Creek near Rimu, Westland, and placed aside by the claim owners as something uncommon, because of its weight and colour.
The Ruby and Sapphire Deposits of Moung Klung, Siam
Authors: Louis Henry
Published: December 2006

The following brief notes on the occurrence of these gems in one of the least known portions of the Siamese ruby fields may prove of interest, as the particular district to which they refer has very rarely, if ever, been visited before by any European, whilst nothing at all has ever been written on the subject as far as I am aware. The notes are chiefly extracts from my journal for the months of May and June 1892, which I venture to present with as little modification as possible, in the belief that a description written on the spot is likely to give a more correct and vivid, even although it be a less highly finished picture of the locality than can be attained by any subsequent elaboration.
On Fulgurites from Griqualand West
Authors: Rutley Frank
Published: December 2006

Through the kindness of Professor D. Hahn of the South African College, Cape Town, I received, some time since, a series of specimens of fulgurites which were collected in the vicinity of Griquastad.

In this locality Professor Hahn informs me that there is a particular sand hill which is noted among the farmers living in the neighbourhood for the frequency with which it is struck by lightning during thunderstorms.
Note on some Inclusions in Quartz
Authors: Rutley Frank
Published: December 2006

In a quartz crystal, slightly over 2¾ inches in length, which has been in my possession for many years, and was stated to come from Derbyshire (possibly Castleton), there is a curious white cirrous inclusion which describes a graceful feather-like curve, and consists of a series of nearly parallel lines of colourless and transparent to opaque snow-white grains, which, under the microscope, are seen to be at times well defined rhombohedra; but for the most part they present the appearance of thorn. bohedra which have been more or less eroded, and they are so ranged in lines that one rhombohedron lies with one pair of faces slightly above or below the corresponding pair of faces of the succeeding rhombohedron, thus giving the line a distinctly serrated edge.
Chemical Analysis of the Meteoric Stone found at Makariwa, near Invercargill, New Zealand, in the year 1879
Authors: Fletcher L.
Published: December 2006

As the preliminary examination of the Makariwa stone had already indicated to Professor Ulrich the presence of mineral constituents having the physical characters of olivine, enstatite, glass, a substance resembling glass, nickel-iron, troilite, magnetite, hydrous oxide of iron, and possibly chromite, the quantitative chemical anslysis presented obvious difficulties, among which may be specially mentioned the fact that one chemical element (iron) enters into the composition of each of the above fine-grained and closely intermingled constituents. This chemical examination I was invited to undertake by Professor J. W. Judd, F.R.S., through whom the two fragments of the stone sent to this country by Professor Ulrich have been generously presented to the British Museum.
Nantokite from New South Wales
Authors: Liversidge A.
Published: December 2006

Some specimens of this rare mineral have recently been kindly forwarded to me by Mr. J. R. McKay, Manager of the Broken Hill South Silver Mining Company, New South Wales, together with a report upon them by Mr. J. O. Armstrong of the above mine, and Mr. A. D. Carmichael of the Broken Hill Proprietary Block 10 mine, as follows :—

“Mineral found at the Broken Hill South Mine, at the 300 feet level in the carbonate of lead stopes, below original water level.
On an Accurate Method of Determining the Densities of Solids
Authors: The Earl of Berkeley
Published: December 2006

In the course of some researches on the relation between the chemical constitution and the crystalline form of substances, I found it necessary to attempt an accurate determination of the densities of crystals.

Messrs. Playfair and Joule, in 1843, in the course of similar researches, determined the specific gravities of numerous salts by the use of an instrument which showed the actual volume of the solid investigated. This method was found to be subject to many errors, and they abandoned it for one which is the prototype of that ordinarily used in accurate work at present.
Enargite
Authors: Spencer L. J.
Published: December 2006

Argentina.--L. Brackebusch (Las Especies Min. de la Rep. Argentina), Anal. Soc. Cient. Argentina, 112, 1878; H. D. Hóskold, Mémoire général et spécial sur les mines, &c., duns la Rep. Argentina (Exposition de Paris, 1889), p. 126, analyses and maps; Catálogo oficial of the Argentine minerals at the Paris Exhibition, 58, 1889; Argentine Rep., Philadelphia Exhibition, 1876, pp. 197, 193; A. Sella, Nachr. d. k. Ges. d. Wiss. zu Göttingen, 317, 1891 (specific heat).
Lewisite and Zirkelite, Two New Brazilian Minerals
Authors: Hussak E. , Prior G. T.
Published: December 2006

This new antimonate was found in the cinnabar mine of Tripuhy, near Ouro Preto, Minas Geracs, Brazil.

The occurrence of cinnabar at this locality has been known since 1810, and a short notice of it is given by Eschwogo in his Pluto Brasilensis, p. 456, which was published in 1883.
On Derbylite, a New Antimono-titanate of Iron, from Tripuhy, Brazil
Authors: Hussak E. , Prior G. T.
Published: December 2006

A Brief notice of this new mineral, which was found associated with Lewisite in the cinnabar-bearing sands of Tripuhy, near Ouro Preto, Minas Geraes, Brazil, has already been given by tile authors in Min. Mag. Vol. XI. No. 50, p. 85. Since that time a sufficient amount of material (1½ grms.) has been separated from the sand to permit a more detailed investigation of its crystallographic and chemical characters.
On the Chemical Composition of Zirkelite
Authors: Prior G. T.
Published: December 2006

In a previous paper (Min. Mag. XI. 1895, p. 80), the result was given of an analysis of the new mineral, Zirkelite, which was discovered by Dr. Hussak in association with baddeleyite in the decomposing magnetite-pyroxenite of Jaeupiranga, S. Paulo, Brazil.

In that analysis only a small amount of material (less than a quarter of a grin.) was used, and no very serious attempt was made to separate small percentages of rare earths in the main zirconia precipitate.
On the Micas of the Three Rock Mountain, Co. Dublin
Authors: O'Reilly J. P.
Published: December 2006

The micas presented by the granites of the Co. Dublin have been analysed by Haughton, and determined by him to be margarodites and lepidomel~lnes (see Proc. Roy. Irish Ac. Vol. VI. 1855, pp. 176-79, and Quart. Journ. Geol. Soc. Vol. XV. 1859, p. 129). In this latter paper he says:--" In my first paper on the Granites of Leinster (Quart. Journ. Geol. Soc. Vol. XII. 1856 p. 171), I have mentioned the black mica which is found accompanying the white margarodite of the Leinster granite in small flakes, and noticed the curious fact that these flakes are sometimes physically embedded in the plates of white mica without injuring their fissility or lustre, hut always eifecting a reduction of about 20° in the angle between the optic axes of the latter."
On Nemalite from Afghánistán
Authors: Mallet F. R.
Published: December 2006

In 1887, when I was in charge of the Indian Geological Survey laboratory, a specimen of a mineral recently discovered in Afghanistán was sent to Calcutta by the British Agent at Kábul, with a request for information as to its nature and value. It proved to be nemalite, and a quantitative analysis of it, which was subsequently made by Mr. T. Blyth, is published in the fourth part of A Manual of the Geology of India, p. 161. As it seemed possible that the mineral might be capable of some useful application if plentiful, and it was in any case of mineralogical interest, a request was made to the Agent for further information about it, including the locality where it was found, and for additional specimens,
On Tripuhyite, a New Antimonate of Iron, from Tripuhy, Brazil
Authors: Hussak E. , Prior G. T.
Published: December 2006

This new antimonate was found in the cinnabar-bearing gravel of Tripuhy, Minas Geraes, Brazil. The minerals associated with it in the gravel, including the two new titano-antimonates lewisite and derbylite, have already been described in this Magazine (Vol. XI. No. 50, p. 80, and No. 52, p. 176). The original source of the lewisite and derbylite has been proved to be the muscovite-schists accompanying itabirite in the neighbourhood of Tripuhy, From these schists, doubtless, is also derived the tripuhyite, although as yet this new mineral has only been found in fragments loose in tbe gravel, and not intergrown with fragments of the muscovite-schists as is often the ease with both lewisite and derbylite.