The daily morning journal and courier., 1898-01-11
SAPPHIREs IN MONTANA.

~>~-~--N~AN e*SeSAAtiOiis oStG1ol iDNNltiSS are now known and several distinct modes of occurrence. They were first found in transported gravels along the bars of the upper Missouri; then they have been found in the earthly product Of decomposed dikes, and lastly further down In the unaltered igneous rock it. self. The succession thus presents a close parallel to the history of the dia- mond workings in South Africa. The first published description of the Mon- tana sapphires was by the late Dr. J. Lawrence Smith In 1873. He said:
 These pebbles were first found on the Missouri river near its source, about sixty-one miles above Benton. They are obtained from bars on the river of which there are some four or five within few miles of each other. Considerable gold is found on these bars, 1t having been brought down the river and lodged there, and the bars are now being work ed for gold. The corundum Is scattered through the gravel, which is about five feet deep, upon the rock bed. Occasion- ally it is found in the gravel and upon the rock bed in the gulches, from forty 10 fifty feet below the surface, but 1t is very rare in such localities.''
 In 1891 the first serious attention be- gan to be paid to the mining of sap phires in this district. The bars con- sist of an auriferous glacial gravel, and in working them for gold, sapphires were obtained as a by-producr. By 1890 com- panies began to be fotmed and claims were taken up and examined with a view to sapphire mining. The region extends for some six miles along the Missouri river, the central point being Spokane Bar, twelve miles east of the city of Helena. Other names, such as Emerald bar, were given to the different points of the area. The gravel rests on slaty bedrock, and the author found | minerals, besides gold and sapphires, Among these are small crystals of white topaz, garnets in rounded grains, often of rich color and miscalled rubies; cy- | anite, stream tin, cha1cedony and limon- ite At Ruby Bar two facts of great | significance were encountered, bearing on the age of, the gravel and the source 1 of the gems. The writer saw and meas lired mastodon ttisk three feet long | imbedded in the sapphire layer of the gravel. and a dike was found cutting | the slaty bedrock beneath.
 Two years before-indeed, in 18S9-- | the writer had seen some specimens of a trachytic rock, inclosing weli-defined ! crystals of sapphire similar to those of Eldorado Bar, from a dike further up the river. These facts, which were re- | ferred to in the Gems and Precious l Stones of North America" {p. 491, and 1 the Appendix (p. 341), sufficiently show 1 ed the source of the gems as coming from the erosion Of dikes of igneous l rock
 More recently sapphires have been l found throughout a considerable district l lying some seventy-five to one-hundred | miles east of the Missouri bars, the 1 principal point being Yogo Gulch, oh the Yogo fork of Judith river near its headquarters, In Fergus county, Mon tana, on the eastern slope of the Little Belt Mountains The nearest town is Utica, fifteen miles to. the northwest, in the same county. The sapphires occur over a somewhat extended area which is being explored and laid out in claims. They are imbedded in a yellow earth material, from which they may be washed out by sluicing, as for gold, the heavy crystals gathering at the bottom. S. $. Hobson, of Great Falls Mont, the l original discoverer of the gems at Togo Gulch, states that at that point there
 are two veins (dikes?) containing sap phires, which have been traced for a
 distance of 7,500 to 5000 feet In an east and-west course, about eight hundred
 feet apart. One of these is seventy-five feet wide, and consists of a yellow earth" G e., completely decomposed). It has been found that what was sup posed to be the end of the vein" is
 really 8 fifty-foot fault and that the
 vein can be traced very much further
 In working down to a greater depth
 the unaltered igneous rock has been
 reached
 Other localities are also coming to light in the same state; one of these
 is "t Rock Creek, Granite county, thirty
 miles from Phillipsburg, where the
 gems are reported of good blue color
 with other tints, and some pale rubies. Another is on Cottonwood Creek, eight
 cen miles from Deer Lodge, the stones
 being of varied colors, red pink yellow
 and occasionally blue. The third has
 been recently announced in Choteau
 county.
 We have here two distinct types of
 specialization in the same mineral
 from the same state and produced ap-
 parently under similar conditions in
 igneous rocks. It will be extremely in
 teresting to learn, by further exp1oita-
 ton and study, whether these two types
 bear any fixed or definite relation to the
 particular variety of eruptive rock ir
 which they occur. The accounts thus
 far given of the rocks examined seem
 to suggest such a possibility.
 t~ to the value of the early Montana
 sapphires in jewelry, it is hardly possi-
 ble yet to predict how far it may be
 really important Much beautiful ma
 terial has already been obtained but
 little of high value Those from the
 Missouri bars had wide range of color
 light blue, blue-green, green and pink
 of great delicacy and brilliancy, but moi
 the deep shades of blue and red that are
 in demand for fine jewelry As semi
 precious or fancy" stones, they have
 value however.
 Tho Yogo Gulch-Judith river region is
 more promising, the colors varying from
 light blue to quite dark blue, including
 some of the true "cornflower' tint SC
 much prized in the sapphires of Ceylon
 Others incline to amethystine and al.