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two or three times, and no rubies were discovered, the whole sand in the basket, which by this time had been reduced to fragments of the size of a pea, was thrown aside.
(8) My experiments.—When I visited this pit it showed signs that it had not been worked for a long time. I therefore expected to get good results. My trials were repeated for three days, each day working for eight hours with 12 coolies. I he coolies were carefully watched, not only while digging, but particularly during the operation of washing. I was therefore quite sure that any theft of stones was impossible. I proceeded in the same way as the natives were accustomed to do. The ruby-bearing sand, when brought out of the pit, was a dirty, clayey earth which made any mineral, ever che pure white quartzite pebble, perfectly indiscernible ; 10 pick out any ruby from this stuff in the short time within which it was brought from the pit to the river would, in my opinion, have been impossible. I even doubt whether the men working in the pit could have abstracted any stone provided it were not an exceptionally large one, so completely did the brown clay conceal the true nature of every pebble or stone. After the first washing there remained a gravel chiefly composed of white quartzite pebbles and a finer sand composed of various rocks and minerals. When the larger pebbles were removed and the finer sand was repeatedly washed, there was left a sand consisting chiefly of quartzite in various colours, those of milky colour prevailing, numerous spinels, a few crystals of hæmatite and occasionally a fragment of titanite or schorl (black tourmaline), but no rubies. It must particularly be mentioned that all these minerals were found in angular fragments, having sharp edges; hardly a single specimen was rolled. This is certainly a proof that they could not have been transported for a long way, or else they would have lost their angular shape.
I paid of course special attention to all “red” minerals, but they all proved to be spinels, not a single ruby being amongst them. The spinels were all of the same poor colour, dark purple, nearly black, and none of the fragments were of any size worth mentioning. The surface of the spinels had a peculiar appearance ; it was honeycombed and the cells were filled with a yellow, soft mineral which I suppose to be hydroxide of iron, and which could be removed entirely by washing and brushing. This may be considered as the first sign of superficial disintegra. tion. Specimens were not unfrequently met with, which had turned into hydroxide of iron, still preserving, however, their original shape.
(b) Do the Namsèka ruby-mines contain rubies or not p-The first samples of rubies which were sent by Lieutenant Daly, Superintendent, Northern Shan States, to the Government of Burma, and which were said to have come from the Mainglôn ruby-mines, were exceedingly fine specimens. They were not large, but of very good colour, some of them nearly flawless and nearly all well crystallized, or if fragments, showing at least a few crystal faces; the edges were all sharp, and not water-worn. A mine producing such stones was certainly very promising, and I was therefore much surprised that I did not find during these three days, with 12 coolies working 8 hours each, a single ruby, and not even a fragment. This was most surprising. as it might fairly be expected that the trials were sufficient 10 prove the existence of rubies if there were any. I therefore felt inclined to think that ihe Namseka ruby. mines must have been either worked out, or that they never produced any rubies at all. As they were not exhausted, that is to say, as the total of the alluvial deposits
had not been exploited, I could only accept the conclusion that they did not contain any rubies at all.
Strange to say this conclusion was supported by a most remarkable story about the origin of the rubies sent to the Government. When the Thibaw Sawbwa sent one of his officials to Namsèka to get samples of good stones from the mines, none could be procured. The man therefore went over to Mogôk, where he purchased the stones which were handed over to the Sawbwa as “Namsèka rubies.” I give this story as it was told me, and I do not venture to use it in any way to support my views about the value of the Namsèka ruby-mines. I must, however, mention that it was told voluntarily to me, and thal the informer did not know the view I held about the mines.
On my way back, passing Thibaw, I told the Sawbwa my doubts as to the Namsèka mines; but he produced a large tray of rubies, amongst which were some excellent stones of good colour which in their appearance perfectly agreed with the stones forwarded by Lieutenant Daly to the Government; and he assured me that all these stones came from the Namsėka mines. To do him justice, I must admit that the samples shown to me contained all sorts of stones, rubies of different colours and shapes, rolled and crystallized, numerous fragments of spinels, of the same appearance as the Namsèka spinels, and a number of minerals, such as are asso. ciated with rubies and spinels. Had these samples actually been bought at Mogôk The man who bought them would have shown a good deal of foresight by also buying minerals which, though valueless in themselves, are found togeiher with rubies, so as to make the fraud a complete one. I must admit that with these reflections and in the face of the positive statemer.ts of the Sawbwa, I do not feel justified in giving a final decision about the value of the Namsèka ruby-mines without having examined them again, and for a longer time.
Several questions, however, first require answering, namely,
(a) Were the ruby-mines which I visited and examined actually those from which the stones in the possession of the Sawbwa had been obtained ? As to this There can be no doubt that I actually visited the place from which the rubies were stated to have come. The mine was fenced in, there was an old guard-house to prevent outsiders from digging, and there is no room for any other ruby-bearing deposit round Namsèka. Besides, the Sawbwa was most anxious to learn something about his valuable mining property, so that I do not see any reason why he should have deceived me by sending me to the wrong place. Furthermore, Mr. Hertz, who has stayed for several months at Mainglôn, has only heard of one rubymine near Namsèka; and he would certainly have heard if there had been more mines from which rubies had been extracted, along the bank of the Nampai, if such mines were in existence; because, as far as I know, the first information about the Mainglên ruby-mines came through Mr. Hertz. Taking everything into consideration there can be no doubt as to the identity of the “Namsèka” ruby-mines.
(6) The question as to the locality having been answered in the affirmative the next question to be answered is— Are the rubies found in certain strata, or are they to be found irregularly distributed amongst the alluvial deposits described in paragraph 2(c)? If the rubies are confined only to a certain stratum or strata, then I must admit that either my operations did not touch such or else that they were completely exhausted by former diggings and had consequently disappeared. Now, from the nature of these deposits I doubt that regular beds existed, for the seclion as exhibited in the pit shows clearly that there is no regularity as regards bedding; the theory of a regular ruby-bearing bed must therefore be dismissed as not being in accordance with the nature of the deposits, and it is more likely that the rubies are distributed irregularly, like any other pebbles or minerals through the whole of the deposits. This may, however, be restricted in some way; there may have existed a pocket of sand or yravel which was particularly rich in rubies, and it may have been from this pocket that the Sawbwa's stones came. This pocket having been completely worked out, the other strata do not contain rubies at all or only in great scarcity. It seems to me that this theory about the occurrence of the rubies is the more probable one, but it can only be tested by a repeated and more extended examination.
5. The origin of the rubies.-However, supposing the rubies were actually found in the Namseka; from the way in which they were found, there cannot be the slightest doubt but that they are not in their primary matrix. They form part of the river deposits, and have been transported by the river, like other stones, from some spot higher up, and they no more originate in the spot in which they are found than the ordinary river gravel. In paragraph 2, I particularly mentioned that no crystalline limestone, the original matrix of rubies, has been found yet. These two observations prove that the rubies cannot come from the immediate neighbourhood of Namsèka, although from their shape it may be concluded that the original matrix which yields the rubies cannot be very far away.
Now, fortunately there is absolute proof that the rubies cannot have been washed down by the Nampai. I examined the deposits of the Nampai around Mainglôn and did not find a ruby or spinel or even fragments of these stones. As they extend to about 10 miles east of Namsèka, the locality from which the rubies came must necessarily be situated between Namsèka and the western limit of the river gravels of Mainglon. As there is, however, no crystalline limestone, we must suppose that they were brought down by a stream coming from the north. The only stream of importance is the Mogôk stream, which joins the Nampai about a quarter of a mile above the Namsèka ruby-mines, and it may therefore be supposed with a great degree of probability that any rubies found in the Namsèka mines have been washed down from the ruby-mines district by the Mogaung river.
6. Probable extension of Ruby-bearing sands in the valley of the Nampai and Mogok streams. Having in the previous paragraph pointed out the way in which the rubies said to have come from the Namsèka mines may have been transported, the question to be answered is whether there is any probability of any more ruby-producing localities being discovered along this way. This question may be answered in the affirmative, and it may be stated that there is the greatest probability of discovering such deposits along the bank of the Mogôk stream, but that the chances get fewer by going farther down the Nampai, provided there is no other feeder from the ruby-bearing strata of the Ruby Mines district. From the nature of the deposits in which rubies are found it may, however, be concluded that they nowhere cover a large area ; at suitable places, in small ravines or behind a hill projecting into the river, they may be looked for and met with, but these pockets would soon be exhausted ; and I therefore doubt whether it would pay a European company to work these deposits the real value of which has, moreover, not been ascertained,.
The following is a summary of the facts which have so far been obtained as regards the occurrence of ruby-bearing deposits in the valley of the Nampai, generally known as the Mainglôn ruby-mines :-
(a) the rubies are not found in their primary matrix ;
sand ; they have therefore been removed by the action of the water
from the place when they originally existed ; (c) the river deposits (gravel and sand) do not form a continuous layer
along the banks of the river ; (d) they are found at isolated places, which were suitable for their deposit
and preservation, thus forming pockets of very limited horizontal extension, and also hardly reaching higher up than 50 or 60 feet above
the low water-level; (e) there is, however, every probability that along the banks of the Mogok
stream and Nampai more such pockets as the Namsèka ruby-mine may be discovered; the chances, however, get less with increasing
distance from the place where the Mogôk stream joins the Nampai ; c) unless a large number of such pockets are discovered, it would not pay
systematic exploitation, even should rubies be found; (8) it is still doubtful whether the Namsèka ruby-mine ever produced rubies,
or whether it will produce them in the future.
Note on the Tourmaline (Schorl) Mines in the Mainglon State : by Fritz
NoeTLING, PH.D., Palæontologist, Geological Survey of India.
1. Situation of the mines. The mines are situated in the broad valley which extends north of the town of Mainglôn, from north-east to south-west for a distance of about 5 miles with a maximum breadth of nearly 2 miles. The geographical position may be Long. 96° 44', Lat. 22° 46'. The valley is traversed by the Nampai, which, coming from the hills to the north-east, slowly makes its way through the broad plain until it disappears again as a wild torrent in the narrow gorge which forms the western outlet of the valley. The mines are situated on both sides of the Nampai along the slopes. The principal mines are near the villages of Naungdaw and Naungheng, about 2 to 3 miles to the north of the town of Mainglôn. No mines are near this place itself.
2. Geology: (a) Gneissic and submetamorphic formations. -As regards the azoic formations they are the same as those observed in the neighbourhood of Namseka, and everything that I have said about these formations in my report on the Namsèka ruby-mines also applies to them as far as the country around Mainglon is concerned. The gneiss is particularly developed north and north-east of the Nampai, while the submetamorphic shales are found in the south and the west. Mainglon itself is situated on a low hill projecting to the north, which is formed by green shales, dipping towards the west, covered by a thick layer of river conglomerate of about 50 feet in thickness.
(6) Alluvial deposits. Amongst the alluvial deposits found in the Nampai valley we can distinguish two groups: (i) an older one consisting of conglomerates and red clay, and (ii) a younger one consisting chiefly of black tough paddy-soil. While the first group is found up to heights of about 200 feet above the present level of the river, the second one is strictly limited to the low plains.
(6) (i) The older river deposits. 1. Conglomerates. The conglomerates which form, so far as is known at present, the basis of the older alluvial deposits consist chiefly of well-rounded smooth pebbles of quartz-rock in various sizes, from small grains up to the size of a man's head and over. Other rocks are scarce, and only occasionally a small pebble of blue silicious shale, or rotten schistose sandstone is found; not uncommon are well-rounded pebbles of black tourmaline (schorl) reaching the size of a walnut. These have sometimes their original crystal shape preserved still, but they always show that they were much water-worn; much scarcer evidently is the red tourmaline, as I did not succeed either in discovering a specimen in situ or in obtaining samples of it from the natives. The only sample I have seen I received through Lieutenant Daly; it was a small fragment of a crystal of pale pink colour stained with flaws and much rolled. The natives stated that occasionally big specimens are found which are sold at a high price, but they are very scarce. They even say that small specimens of hardly any value are not common. Besides the minerals mentioned, I found a fragment of rock crystal and a piece of agate. The monotonous composition of this conglomerate proves clearly enough that it is made up from the débris of a country where there was only a small variety of strata; very likely the strata consisted chiefly of gneissic and granitic rocks. The pebbles are cemented by a coarse gritty clay of yellowish colour, thus forming a compact hard mass, which is hardly affected by ordinary tools, as the pickaxe rebounds on the smooth rounded quartz-rock pebbles.
It is very likely that the conglomerate, like all other strata of similar composition, contains a smalt quantity of gold which was extracted by the miners. I do not say that gold-washing operations were their chief object, but I feel strongly inclined to think that they gave the original start and that in the progress of the work the tourmalines were discovered and the exploitation of these stones, highly valuable in the eyes of Chinamen, was gradually substituted for that of gold, although the latter was never quite neglected. I did not, however, succeed in getting information on this point, as the natives were very suspicious lest anything should be known.
II. The red clay.-The conglomerates are everywhere covered by a layer of tough red clay, not particularly gritty, but containing numerous angular grains of quartz-rock and felspar. The clay does not show any sign of bedding, and forms one continuous layer from the floor to the top. Its thickness varies much, as at some places it certainly exceeds 50 feet, while at others it is between 15 and 20 feet. It is most remarkable that clay and conglomerate never alternate, but that they are separated by a sharp limit, the clay being always on the top of the conglomerate, which it conceals perfectly. The soft, rounded features of the low hills round Mainglên are due to this superficial coat of red clay.
(6) (ii) The younger river deposits.— There is not much to be said from a geological point of view about these deposits, although they certainly form a most valuable tract from an agricultural point of view. There is the well-known dark grey or black soil, a tough clay mixed with a high percentage of decomposed organic