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Ch. 3: Precious Gem stones in 1911

Ch. 3: Precious Gem stones in 1911 Page of 105 Ch. 3: Precious Gem stones in 1911 Text size:minus plus Restore normal size   Mail page  Print this page
1064
MINERAL RESOURCES.
majority is rather inclined to grayish pink, and some is greenish gray. Both finely granular and rather coarsely crystallized rhodonite occur. The different colors and textures grade into each other and with the black seams and markings would yield contrasting ornamental mate­rial. The purer pink varieties, with or without the black seams, could be cut into very pretty gems.
OREGON.
Specimens of rhodonite with information on the occurrence have been received from Mr. C. H. Gillette, of Ashland, Oreg., from a deposit near the Josephine County caves. The rhodonite is asso­ciated with black oxides of manganese below a limestone formation. The specimens sent were obtained during prospecting for manganese and had been badly fractured during blasting. The rhodonite is delicate rose pink, and with it is associated gray and a little greenish-gray mineral, also probably rhodonite, and manganese oxides. The texture is very fine grained, nearly compact, so that the material ought to take a good polish. The combination of colors would yield pleasing gems.
SAPPHIRE.
MONTANA.
A large production of sapphires was reported from Montana dur­ing 1911. The output came from the Yogo blue sapphire mines in Fergus County; Eock Creek, in Granite County; Dry Cottonwood Creek, in Deerlodge County; and the Missouri River placers east of Helena. The mines operating in Fergus County were the New Mine Sapphire Syndicate and the Yogo American Sapphire Co. These companies obtain sapphires by mining, disintegrating, and washing a rock matrix. The sapphires obtained here are nearly all blue; those from the other localities are varicolored, and fine blue stones are rare. The Yogo American Sapphire Co. commenced operations in July, 1909, but as no report was received by the Survey the output of this company was not included in the tables of production for the years 1909 and 1910. Mr. H. O. Chowen, president of the company, has supplied statistics of production for the last three years, and this total output is given combined with that of other producers for 1911 in the subsequent table. Consequently the figures given for 1911 are a little high, but the great increase over 1910 is also in a large part due to increased productions from other mines.
The output of the New Mine Sapphire Syndicate was also greater than in 1910. Some fine sapphires are reported to have been found at this mine in 1911, two of which were exceptionally good. One of these weighed 3-1/2 carats and the other 2-1/2 carats and both had a beau­tiful cornflower-blue color. The summer season, in which the wash­ing is done, was better than in 1910, and no cloudbursts occurred to damage the ditch on which water for washing is dependent. The water supply was plentiful and together with the new depositing floors laid down in the previous summer added to the increased pro­duction of gems.
The sapphires mined from the other localities mentioned all occur in placer gravel deposits. On Dry Cottonwood Creek some have tbeen mined by dredging, and one dredge was operated by the Consoli-
Ch. 3: Precious Gem stones in 1911 Page of 105 Ch. 3: Precious Gem stones in 1911
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US Geol. Surv. 1911. Gemstones, Metals.
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