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Introduction

Gbaphh'e Mines at Mount Bopple

Table op Analyses of Mount Bopple Graphite Other Queensland Graphite Deposits Notes on Graphite in New South Wales...

Notes on Some British and Foreign Graphites

Abtipioial Graphite

Concentrating and Dressing Graphite

Uses of Graphite

producmon akd values

PACK

...

.. 10

...

la

GRAPHITE IN QUEENSLAND

With Special Reference to the Mount Bopple Graphite Deposits.

INTRODUCTION.

The following notes have been prepared with the object of making available all that is at present known concerning the occurrence of graphite in Queensland. The principal deposits are at Mount Bopple, in the Maryborough district, where the graphite has been found suflficiently pure for commercial purposes, and where mines are now being worked with a view of supplying the demand which has been created for it.

Graphite occurs in other localities in Queensland, and in the following pages reference will be made to these and to the more important foreign sources of supply. Notes will also be given on the dressing, uses, values, and production of the mineral.

THE GRAPHITE DEPOSITS AT MOUNT BOPPLE.

Position, Etc.

The Mount Bopple graphite mines are situated on the range close to the North Coast liailway between Gympie and Maryborough, being about three miles south-east of Netherby, and about the same distance north-east of Gundiah. The highest point on the Bopple Range is Beacon Peak, 1,900 feet above searlevel, on which has been erected a trigonometrical staff. The peak, known as Mount Bopple, 1,800 feet high, is the most northerly one on the range, and is about three-quarters of a mile distant from the Beacon Peak.

The two peaks, together with Mount Gundiah, which is about a mile south of Beacon Peak, are connected by a low range having a north and south trend, and on both their eastern and western sides numerous steep and rugged spurs lead down to the flat coimtry at their bases. It is on the spurs leading down from the gap between Mount Bopple and Beacon Peak that the graphite-bearing belt of coimtry is situated. The position of this belt, together with other features, are shown on the accompanying plan. (Plate 1.)

Gbolooical Fbaturbs.

Burrum coal measures are the prevailing sedimentary rocks around the Bopple Range, and their intrusion by igneous masses has resulted in the strata being much crumpled and faulted.

Mount Bopple, the northern peak, is made up of syenite, syenitic granite, and hornblende andesite, whilst Beacon Peak is composed of andesite and quartz felsite. The syenite is exposed on the western side of the saddle connecting Mount Bopple and Beacon Peak, and it also outcrops on the surface about 60 feet away from a shaft sunk by Mr. Simpson to prospect the graphite deposits on this side of the range. •Granite and syenitic granite are exposed lower down the slope, and also further north on some of the spurs leading down from Mount Bopple.

Hornblende andesite is the predominating igneous rook on the eastern side of Mount Bopple, and in several places it is seen in contact with the coal measures. With other varieties of andesite it is also exposed in many localities to the north of the range in the direction of Tiaro, about four miles distant, and about a quarter of a mile west of Tiaro, in the banks of the Mary River, a natural section shows its association with coal measures. The intrusion of these igneous masses appear to have disturbed the sedimentary rocks throughout the district, and to have altered seams of bituminous coal to anthracite or graphite.

The occurrence of aplite was also observed at the graphite mines on the western slope of the range. At Simpson's shaft this rock is found in the graphite in the form of small veins about an inch in thickness, which taper out to leaders, and gradually change to a plumose niica. Occasionally the hornblende of the andesite is found in the form of black cleavable crystals about an inch in diameter, and, no doubt, the rumour that wolfram is found in this locality is due to the presence of this mineral.

The coal measures, containing bituminous coal seams, are exposed in the country all round the mountains, and at Tiaro, Gutchy Creek, Munna Creek, Kannighan Creek, and Redbank Creek outcrops are to be seen which show the strata to be undulating, with occasional areas in which all bedding structure have been destroyed.

Between Mount Bopple and Beacon Peak the coal measures are severely contorted, but an easterly and westerly trend can be distinguished, this direction being the axis of a folding movement which has taken place in the measures lying between the two mountains. This is illustrated on Plate 2, Fig. 2.

On the western slope of the Range the bituminous coal has been altered entirely to graphite, while on the eastern slopes the coal, by almost imperceptible stages, has been changed to semi-bituminous coal, anthracite, and graphite. In one locality the graphite rests on anthracite, with six inches of graphitic clay shale between, the beds of graphite, anthracite, shale, and associated rocks being quite imiform and apparently undisturbed. Sections of this are represented on Plate 3, Fig. 1, and Plate 2, Fig. 1. In the latter section the anthracite is divided into a large number of small bands interbedded with shale.

CEOLOCICAL SURVEYOF QUEENSLAND

PLATE I

MOUNT BOPPLE GRAPHITE MINES

'Sca/e cf Chains fo 20 so

///usfraff'ng /?eporton "Cnaph/fe /n Queens /and '

The anthracite is ^ery lustrous and of good quality, but the l>ands are on an average only about an inch in thickness, whilst the bed of graphite, six inches above, is dull and earthy, and shows no perceptible division into bands of varying quality. The beds above and below are shales and sandstones, and there are no intrusive rocks in direct contact with either the graphite or anthracite. Probably the anthracite has been a coal of good quality, and that the graphite originally has been carbonaceous matter mixed with carbonate of iron. The intrusive masses of hornblende andesite in the vicinity might have induced the change from bituminous coal to anthracite at the same time that the carbon contained in the ironstone was changed into graphite. Subsequent leaching would have removed most of the iron, leaving a residue containing about 50 per cent, of graphitic carbon. Plate 3, Fig. 2, shows a section near BulFs graphite mines illustrating the intrusion of the graphite-bearing strata by dykes of hornblende andesite.

Mining Opbrations.

The work of exposing and developing the graphite deposits on the western slope of Mount Bopple are now proceeding at Simpson's mines, and a shaft has been sunk to prove the seams which are exposed on the surface.

The position of the shaft is shown on Plate 2, Fig. 1, the sections of the shaft and the seams being represented on Plate 4. At the first landing in the shaft (marked S. 1 on Plate 4, Fig. 1) a sample was stripped from a seam of graphite four feet thick, and which on analysis yielded 27' 10 per cent, of carbon and 69*20 per cent, of ash. At the second landing (marked S. 2) a 3-foot seam of graphite was sampled, and was found to contain 32*28 per cent, of carbon and 62*40 per cent, of ash. Another sample was taken from a 2-foot seam at the third landing (S. 3) which yielded 18*32 per cent, of carbon and 76 per cent, of ash. Other samples were taken from positions lower down in the shaft, and gave results somewhat similar to the above. The whole of the analyses of the samples taken are tabulated on another page.

The seams which were sampled aggregate eleven feet of graphite, having an average composition of 25'59 per cent, of carbon and 69*30 per cent, of ash. Other bands of shale, aggregating 24 feet in thickness, contain a smaller percentage of graphite, while there is about ten feet of shale in which graphite is not present. Sections which have been exposed in the vicinity of the above workings show that other graphite scams are present interbedded with graphitic shales and sandstones, but their quality has not been ascertained.

The inclination of the strata in the upper portion of Simpson's shaft is at an angle of about 45°, but nearer the bottom the angle of dip is much steeper, and in one place is nearly vertical.

Some old workings, opened many years ago by Mr. C. S. A. Drain, are situated close to the gap between Mount Bopple and the Beacon

Peak. They show the graphite to be of the same general character as that exposed in the workings previously referred to, and they have the same alterations of graphite, graphitic shales, and graphitic sandstones. The rocks contain impressions of Alethopteris a/ustralis and Phyllotheca, and probably bear a close relation to the Burrum coal measures. Samples from the workings were obtained by Mr. W. H. Rands in 1890, who visited the locality when making a general examination of the geological features of the district.* A picked sample from here gave, on analysis, 6'3 per cent, of moisture and volatile hydrocarbons, 72*7 per cent, of carbon, and 21 per cent, of ash. Another sample taken from a number of bands in a section 36 feet wide yielded 7 per cent, of moisture and volatile hydrocarbons, 44*25 per cent, of carbon, and 48*75 per cent, of ash.

The workings at Builds mines show that graphite occurs in several localities on the eastern slope of the range, but operations have been principally confined to four places. No. 1 Workings, situated in a ravine on one of the heads of the north branch of Stewart's Camp Creek, are in the vicinity of the line of contact of coal measures and an igneous rock mass. (See Plate 1.) The rocks consist of clay shales, sandy shales, and graphitic shales, and are much inclined. A seam of graphite, four inches thick, has been exposed in a short underlie shaft, and a sample taken from the face of the workings yielded, on analysis, 3*2 per cent, of moistiu-e and volatile hydrocarbons, 16*3 per cent, of fixed carbon, and 78 per cent, of ash.

No. 2 Workings are in an adjoining watercourse, which also falls into the same branch of Stewart's Camp Creek. The sedimentary rocks here are shales, sandy shales, graphitic shales, and sandstones, together with a bed of graphite and a great number of bands of anthracite. Masses of hornblende andesite occur close to the workings, intrusions of which disturb the shales and sandstones and alter ikeir character. The workings consist of a tunnel driven along the inclined seams of anthracite and graphite to a distance of 38 feet. A section of this tunnel is given on Plate 4, Fig. 1. The graphite from this tunnel contains 11 per cent, of moisture and volatile hydrocarbons, 74*1 per cent, of fixed carbon, and 24 per cent, of ash. A sample of the anthracite, picked from the bands which, altogether, make up about one-quarter of the whole of the five-foot seam, gave the following result : —

ANALYSIS OP ANTHRACrrB BAKDS, BULL'S MIN-B, MOUNT BOPPLB.

Moisture 1*2 per cent.

Vol. Hydrocarbons 8*3 „

Fixed Carbon 90-9 „

Ash 4-6

* Tiaro District : The Coel Measures. Neardie Antimony Mines, and Teebar and Culgoa Copper Mines, by W. H. Rands. By Auth. : Brisb., 1890, p. 8 G.S.Q.P., No. 59).

GEOLOGICAL SURVEYofQUEENSLAND

Sections at the Mount Bopple Graphite Mines

Fig. I

Graphitic Shale itf Graphite

Graphitic and Anthracitic Shale

Anthracite interbedded with blue Shales

Hard blue Shales

Section at N9Z Workings CTunnei), Bull's Graphite Mine, Mt Bopple

Illustrating the occurrence of Anthracite with Graphite

Fig. 2

IVrt Bopple

Beacon Peak

Syenite Ac

Graphite Beds

Quartz Andesite ftc.

Section along the Bopple Range

Showing the crumpling of the Graphite-bearing Coal Measures befween Mt Bopple and the Beacon Peak

No. 3 Workings are situated on the south branch of Stewart's Camp Creek, at the position shown on the accompanying plan. (Plate 1.) They consist simply of some excavations in the bed of a watercourse in which seams of graphite occur interbedded with the shales. About three feet of the graphite-bearing shales have been exposed, but the surrounding features indicate the probability of other seams of graphite being found if a prospecting shaft were sunk close to the present workings.

At No. 4 Workings, which are lower down on the same watercourse, a four-foot seam of graphite has been exposed, and proves to be the largest of those discovered on the eastern side of the range. The cliffs in the vicinity show several small graphite seams interbedded with shales, and possibly others exist whose outcrops are covered by dihris. A short tunnel has been driven into the four-foot graphite seam, a sample from which yielded, on analysis, 3*2 per cent, of moisture and volatile hydro-carbons, 16' 3 per cent, of fixed carbon, and 78 per cent, of ash. A sketch section of No. 4 Workings is given on Plate 4, Fig. 2.

Other places in the vicinity of Bull's workings indicate the presence of several graphite deposits, and as there are here large areas known to be graphite-bearing, and many natural sections of rock exposed which have not been carefully examined, seams of better quality will probably be found as prospecting operations are advanced.

Tablb op Analyses of Mount Bopplb Graphite.

COMPOSITION 07 A3H.

No.

Moifltuie

Mixed

Ash.

andV.H.0.

Carbon.

Silica.

Alumina. 30-20

Lime.

Alkalies. Ac. (by difference).

69-20

61-80

1-90

6-10

5-32

32-28

62-40

58-30

35-80

4-20

5-68

18-32

76-00

58-10

35-60

1-30

5-00

4-46

73-40

55-60

37-20

2 70

4-50

5-26

25-74

69-00

59-00

25-00

4-00

5-22

27-98

66-80

59-80

1-40

2-50

3-20

16-30

3-50

15-60

79-50

2-80

46-30

51-10

1*10

74-10

24-00

-Ash is mainly Silicate of Alumina.

2-40

10-80

82-80

6-20

21-00

44-25

4-40

90-90

4-60

.

Note.— A Uttle iron and magnesia is present in aU samples, but sulphur is absent LOCALITIES FROM WHICH THE ABOVE SAMPLES WERE TAKEN.

No. 1. Simpson's shaft, No. 1 landing, 4-foot seam. No. 2. Simpson's shaft, No. 2 landing, 3-foot seam. No. 3. Simpson's shaft, No. 3 landing, 2-foot seam. No. 4. Simpson's shaft, No. 4 landing, 1 foot 6 inch seam. No. 5. Simpson's shaft, No. 5 landing, 6-inch seam. No. 6. Simpson's shaft, sample from 6-ton parcel prepared for market.

No. 7. Bull's No. 4 Workings, sample from 6-ton parcel bagged for market.

No. 8. Bull's No. 4 Workings, from working face in short tunnel at No. 4: Workings.

No. 9. Bull's No. 3 Workings, from outcrop in watercourse (above No. i Workings).

No. 10. Bull's No. 1 Workings, from 4-inch seam in inclined tunnel.

No. 11. Bull's No. 2 Workings, from 1-foot seam in 38-foot tunnel.

No. 12. Bull's No. 2 Workings, from excavation in bed of watercourse.

No. 13. Drain's old workings, picked sample by Mr. Rands.*

No. 14. Drain's old workings, average sample from bands interbedded with shales, in a 36-foot section (by Mr. Rands).*

No. 15. Bull's No. 2 Workings, bands of anthracite below bed of graphite.

OTHER QUEENSLAND GRAPHITE DEPOSITS.

Mackat District. — The deposits of graphite in Selections 776 and 777, parish of Eton, was inspected in 1896 by Mr. A. Gibb Maitland, who furnished a report (unpublished) concerning their occurrence. . He states that the graphite is associated with beds of shales and quartzites, traversed by what appears to be both interbedded and intrusive masses of igneous rocks.

In one locality on Scrubby Creek, the graphite has been exposed just above the level of the watercourse, and a prospecting tunnel has been driven into it for a distance of 80 feet. In thickness the "vein" averages about 18 inches, and has a perceptible dip to the north-east, while further along the bed of the gully the vein has a thickness of over four feet. About 20 tons of this graphite was bagged for experimental purposes, but the results of the trial have not been ascertained.

Another thin vein of graphite is exposed about eight feet above the one just referred to, but nothing has been done to determine its thickness or quality. Further up the course of the gully another mass of graphite associated with black shale is exposed, and is almost in contact with an intrusive rock. Nearer the head of the gully there are beds of shale exposed, which have been disturbed by these intrusions, whilst indications of the presence of graphite are to be noticed in several places near the same watercourse. In Palm-tree Gully, to the north of Scrubby Creek, graphite is to be found under similar conditions, and in several other localities outcrops of graphite and graphitic shales are also known.

The western side of Selection 777 consists of basalt with underlying shales, and the flanks of Homebush Hill, in Selection 776, are made up of horizontally-bedded shales with interbedded deposits of graphite, none of which, however, have been examined.

The graphite from the localities in this district, according to Mr. Maitland, contains from 15 to 70 per cent, of graphitic carbon, and at the time he made the examination considered the deposits to be worth further attention.

Cloncurrt. — Graphite was discovered near Cloncuny in 1880,* but for many years no further exploration has been made of it. Quite lecently, however, samples of graphite have been received from Hampden, near Goncurry, where a large deposit exists. Most of the material is of an inferior quality, but some portions contain 40 per cent, of carbon. A shaft simk to prospect for copper penetrated a large mass of graphite of unknown dimensions, of which Mr. Jas. Long furnishes the following section : —

Section of Graphdte Deposit^ Hampden,

Decomposed rock

Rar+ly decompose!

Hornblendic(7)rock ^Decomposed dyke rock ^Copper Ore ^Decomposed dyke rock

Graphite & Graphitic

Shale (percentage of Carbon varies from 20 to 40^.)

Stanthorpb DisTRicrr. — Graphitic slate is present in the Silver Spur Mine at Texas, t but its quality does not warrant any consideration being given to it as a commercial product. At Wilson's Downfall, on the New South Wales border, graphite occurs in abundance; but up to the present the deposits which have been found have proved to be inferior in quality. Much requires to be done, however, before any definite conclusion can be arrived at a« to their value.

* Annual Report of the Department of Mines for 1880, p. 31. + Notes on Tin, Copper, and Silver, in the Stanthorpe District, bv L.C.B. Auth. : Brisb., 1904, p. 31 (G.S.Q.P., No. 191).

By

Capb Uf start.* — Deposits of graphite are known at Cape Upstart, on the coast between Townsville and Bo wen, but they have not been developed to any extent. Prospecting operations which are now in progress show that the seam of graphite varies from foiu: to eight feet thick, and is in coal measures close to a mass of igneous rock. The quality appears to be similar to that of the graphite at Mount Bopple.

Gtmpib. — Graphite is intimately associated with the reefs which traverse the slates of this goldfield. The quality is very poor, and of no commercial value.

Croydon. — The granitic and felsitic rocks prevailing on this goldfield contain small quantities of graphite. t In the granite it is found as irregular inclusions, and is much contaminated with clay. In the felsites it is in the form of flakes, very pure in quality, but finely disseminated.

IlAMii/roN GoLDFiBLD. — The quartzites associated with the reefs on this goldfield contain a quantity of graphite in the form of flakes, t

NoRMANBT GoLDFiBLD (Reid*s Creek). — A large deposit of graphite has been found on Rosslyn Run, near Greenbank, but no authentic information has been obtained concerning its quality. §

Yorkbt's Goldfibld. — In CampbeH's reef on this field graphite is associated with pyrites and quartz.

Nbw Guinba. — " The presence of graphite or plumbago has been demonstrated over nearly the whole of the known portion of the Possession, but always as an accessory constituent of the schists; in some cases it occurs in such a quantity as to give a distinctive character to the rocks. In the most graphitic of the schists, although the quantity is proportionally large, to remove the impurities (chiefly quartz) by washing or other means would be too costly to be remunerative. "||

NOTES ON GRAPHITE IN NEW SOUTH WALES.

A deposit of graphite-bearing shale is exposed near Underwood Station, about twelve miles from Wilson's Downfall, near the Queensland border. It is interbedded with sedimentary rocks which have been altered by an intrusive mass of granite. A trial has been made of the graphite by the Springfield Facing Company, Massa-

♦ Mineral Wealth of Queensland, by R.L. J. Brisb. : By Auth. 1888, p. 67 (G.S.Q.P., No. 48).

+ Some Croydon Gold Mines, by B.D. Brisb.: By Auth., 19a5, pp. 9-10 (G.S.QP., No. 202).

I The Hamilton and Ooen Goldfield, by L. C. Ball. Brisb. : By Auth., 1901, p. 4 (G.S.Q.P., No. 16S).

§ Annual Report of the Department of Mines, 1887. Brisb. : By Auth., 1888, p. 54.

II Geological Observations in British New Guinea, by A. Gibb Maitland. Brisb. : By Auth., 1892, p. 32 (G.a.Q.P., No. 85).

GEOLOGICAL SURVEYofQUEENSLAND

Sections at the Mt Bopple Graphite Mines

Fig. I

Section of N9Z Workings Bull's Mine

Showing the position of the beds of Sandstones, Shales, Graphite and Anthracite

K X ^ ^

^ * it K

* H 1^ f. rt

> Hornblende Andes i+o

^ 5ha I GB, So f^ cysteines & Greywackos

Section near Bull's Graphite Mines

Showing the intrusion of the Graphite- boa ring beds with Hornblende Andesite

///usfraf/n^ Report on ^^ Graph /fe /n Queens/and/'

chusetts, and the following report was furnished: — '*We are positive that it would make a very good faoing, and could be used to advantage wherever Grennan " lead" (plumbago) is used in the manufacture of foundry facings. It is true that it would probably be impossible to ship it to this country at the price we pay you, as we can buy a powdered Grerman lead at IJ cents in New York, or an Italian lead, which closely resembles it, at about 16 dollars per ton. On any work in the foundry where the facing is used wet — such as dry sand or cores — it would be a very good article indeed, and in any market you could reach we think it would pay to have same used." — (Min. Resources of N.S.W., by E. F. Pittman.)

In New South Wales deposits of graphite are also known to occur at Grafton, Mudgee, Fairfield, Hillgrove, Tobin's Creek, Cowell Creek, near Port Macquarie, Dundee, Tenterfield, Pambula, Cordeaux River, Plumbago Creek in the county of Drake, and at the head of the Abercrombie River. f

NOTES ON SOME BRITISH AND FOREIGN GRAPHITES.

With the occurrence of so many deposits in Queensland, and so many possibilities of finding a higher grade graphite than that already known, some information concerning foreign deposits might prove useful. There are some discrepancies and apparent inconsistencies in the data given below, but no means are available for checking the accuracy of the varying statements made in the works consulted, so the information can be taken for what it is worth.

Cetlon. — The mines of Ceylon are the largest in the world, and

the graphite produced is of such high quality that it may be taken

as the market standard. An average analysis of high-grade Ceylon graphite is as follows : —

CBTLON HIGH-GRADB GRAPHITE.

Volatile matter O'SIO per cent.

The country rock is granite, gneiss, &c., partly decomposed, in which the graphite, in the form of coarsely foliated masses, occurs in true fissure veins.

Italy. — ^The mines at Pinerolo district of Piedmont produces a graphite containing from 10 to 80 per cent, of carbon. The raw material, after grinding, contains, on an average, about 61 per cent, of pure graphite.

Bavaria. — At the Passau mines the graphite occurs as an impregnation of gneissic rooks, and is closely associated with beds of limestone. The graphite is of poor quality, the best undressed material containing 53*8 per cent, of carbon, the inferior 31*72 per cent. The dressed article contains 89*2 per cent, of carbon, and the waste material from 223 to 36*8 per cent.

Cumberland, England. — ^The old Borrowdale graphite mines have been practically idle for the last forty years, and are exhausted. The graphite is in the form of nests and lumps, and occurs in veins of quartz and calcite which traverse greenstone porphyry. The graphite produced from these mines was a fine flake variety, used principally in the manufacture of lead pencils.

Buckingham, Quebbg. — In these Canadian mines the graphite is disseminated in gneiss, &c., the deposits varying in thickness from a few feet to 25 feet. The proportion of graphite to rook is from 10 to 50 per cent., but in one particular bed, 20 feet in thickness, the average yield is 20 per cent, of graphite. The raw graphite has the following average composition, and considerable quantities of this rock has been mined : —

ANALTSBS OF BUCKINGHAM GRAPHTTB.

Hygroscopic moisture 1740 per cent.

Soluble in HCl 19-4fi7

Insoluble 56*408 „

Carbon 22*386

Ontario. — Considerable quantities of graphite are obtained at the mines at Renfrew, but it is stated that the industry is only carried on profitably when the percentage of graphite in the gangue is more than 15 per cent. At the Black Donald Mine the total amount of graphite in the product is about 65 per cent., of which about 45 per cent, is amorphous, the remainder being the flake variety. Some portions of the deposit yield a graphite containing as much as 80 per cent, of carbon, whilst low-grade portions contain about 25 per cent, of carbon. The graphite occurs as a vein in crystalline limestone, and is associated with seams and pockets of chlorite, and is close to schistose rocks.

At the McConnell Mine, near Perth, Lanark County, the product, which is in a flake form, contains much less carbon than that at the Black Donald Mine. The country rock is limestone, and the graphite occurs in zones or veins several hundred feet long.

Bohemia. — The Schwarzbaoh-Kruman deposits are lenticular in shape, and are associated with limestones. The graphite is much desired for pencils, and in being compact and without foliation is admirably suited for this purpose. The refined graphite contains from 50 to 60 per eent. of carbon.

Sttria. — The deposits in this locality are associated with strata belonging to coal measures. The graphite produced contains from 73*8 to 88*5 per cent, of carbon, and analyses show it to have the following average composition : —

Alumina

Silica ...

18-04 „

Carbon ...

77-95 „

GEOLOGICAL SURVEY ofQUEENSLAND

Sections at the Mount Bopple Graphite Mines Fi^.l

S. I Four-fisof Graphite Seam S*Z Three-foot Graphite Seam

Graphitic Shales

&.STwo-fbot Graphite Seam

S. 4 One -fbot-six- inch Graphite Seam

Graphite Shales S< 5 Six-inch Graphite Seam

Graphitic Shales

Section of Shaft at Simpson's Mine Showing the position of* the Graphite Seams (See accompanying table for analysis)

Fi«.Z

Section across the South Branch of Stewart's Camp Creek Showing N?4 Graphite Workings at BuiPs Mine

///ustraf/ng /Report on "Cr&ph/fe /n Queens/snc/''

As the silica is the principal impurity, the graphite is very refractory, and in consequence is in great demand for the manufacture of crucibles.

Irkutsk, Sibbru. — At the Batugol mines the graphite is of very fine quality, and much used in pencil-making. It occurs as fibrous lumps in veins traversing granite and diorite, and is closely associated with an altered limestone.

TrcoxDKROGA, Nbw York. — The mines at this locality are worked by Dixon, and are the principal source of supply in the United States. The rock as mined averages ten per cent, of graphite, but deposits are said to be worked which yield not more than six per cent. These deposits are stated to be " elliptical chimneys in gneiss, which have been filled with calcite and graphite."

Austria. — The Northern Moravian mines produce a graphite containing 53 per cent, of carbon, and 44 per cent, of ash.

South Dakota. — ^The graphite found at Rockford, in this State, contains from 26 to 41 per cent, of carbon, which, without being accouipauied by other higher grades, is considered too low in quality to profitably mine.

Mexico. — Mexican graphite varies from 40 to 50 per cent, in carbon contents.

Corona, U.S.A. — "Corona" graphite contains 57 per cent, of carbon and about 40 per cent, of ash. It is the material now being used by the Southern Pacific Railway Company for paint, fine lubrication, foundry facings, and hot-box grease.

India. — Samples have been submitted to the Imperial Institute from the Chatisgarh district, and were foimd to contain respectively 4095, 37, 79-91, 6967, 6370, and 54*73 per cent, of fixed carbon. The saiuple containing 799 1 per cent, of carbon was not considered sufficiently pure to be used in the making of crucibles, and could only be utilised for stove-polishing and similar piurposes, and would be worth about £10 per ton. The remaining samples, except that containing 69'67 per cent, of carbon, were said to be of very little value. It is further stated that the supply of graphite having less than 85 per cent. of carbon was very much in excess of the demand, and that in consequence such quality could only command a low price.