JEWELRY-QUALITY MODIROVAL AMMONITE, MADAGASCAR
Wood tin is a little-known and poorly studied kind of jewelry stones. This article gives information on mineral composition and gemology of jewelry-quality species of wood tin of Dominion Creek gold placer, Canada. The placer occurs in the primary gold-bearing area of Canada—Klondike known since the late 19th century. The placer is alluvial and valley, it was formed during the Quaternary period. Wood tin is an associate component of the placer and is connected with the rhyolitic tin deposits. The internal structure of wood tin is governed by the graded-zonal alteration of dark-brown, brown and light-brown layers of spherolitic-texture cassiterite. By the data of X-ray phase analysis, wood tin is mostly composed of cassiterite, to 97%, also quartz and potash feldspar are present. The optical–petrographic and electron probe research shows that wood tin is formed by cassiterite crystals of coarse to cryptocrystalline size, with different contents of impurity elements. Wood tin contains many pores. Color zonality of wood tin is conditioned by structural features and concentration of Fe. Various coloring and texture of wood tin in combination with high hardness and brilliant luster allows the mineral to compete with widely known gem stones. The jewelry-quality wood tin can be extracted as a by-product during mining of tin deposits and gold placers, which makes it a highly profitable kind of semi-precious raw material.
: 553.8: 553.45 (71)DOI
: Petrochenkov D. A.
Petrochenkov D.A., Candidate of Geological and Mineralogical Sciences,
Assistant Professor, e-mail: email@example.com,
Russian State Geological Prospecting University named after Sergo Ordzhonikidzе
(MGRI-RSGPU), 117997, Moscow, Russia.Key words
Wood tin, cassiterite, gold, gen stones, tin deposits, placers.References
1. Bukanov V. V. Tsvetnye kamni i kollektsionnye mineraly [Gem stones and collectible minerals], Saint-Petersburg, 2014, 464 p.
2. Makeev B. V., Politov V. K. Olovorudnye mestorozhdeniya zarubezhnykh stran [Tin deposits in foreign countries]. Itogi nauki i tekhniki. Seriya «Rudnye mestorozhdeniya». 1991. vol. 23, 192 p. [In Russ].
3. Pavlovskiy A. B. Mineral'no-syr'evaya baza mira i Rossii: sostoyanie, osvoenie i perspektivy razvitiya. Olovo [Minerals and raw materials in the world and in Russia: State-of-the-art, extraction and development prospects. Tin]. Mineral'noe syr'e. Seriya «Geologo-ekonomicheskaya». 2008, no 27, 96 p. [In Russ].
4. Patyk-Kara N. G. Minerageniya rossypey: tipy rossypnykh provintsiy [Minerageny of placers: Types of placer provinces], Moscow, IGEM RAN, 2008, 528 p.
5. Petrochenkov D. A. Formatsionnye tipy olovorudnykh mestorozhdeniy, perspektivnye na kollektsionnye i yuvelirnye kassiterity [Formational types of tin deposits, promising collectible and jewelry-quality cassiterite]. Izvestiya vuzov. Geologiya i razvedka. 2007, no 2, pp. 31—35. [In Russ].
6. Petrochenkov D. A., Chistyakova N. I. Osobennosti mineral'nogo sostava derevyanistogo olova mestorozhdeniya Dzhalindinskoe (Rossiya) [Features of mineral composition of Dzhalinda wood tin deposit (Russia)]. Novye dannye o mineralakh. 2011. Issue 46, pp. 55—60. [In Russ].
7. Petrochenkov D. A. Mineral'nye i strukturnye osobennosti yuvelirnogo derevyanistogo olova [Mineral and structural features of jewelry-quality wood tin]. Izvestiya vuzov. Geologiya i razvedka. 2017, no 4, pp. 36—44. [In Russ].
8. Polyanin V. S., Polyanina T. A., Dusmanov E. N. Mineral'no-syr'evaya baza tsvetnykh kamney Rossii: perspektivy ee osvoeniya i razvitiya [Mineral and raw materials base of gem stones in Russia: Prospects of development and expansion]. Razvedka i okhrana nedr. 2015, no 9, pp. 66—76. [In Russ].
9. Duk-Rodkin A., Barendregt R. W., White J. M. et al. Geologic evolution of the Yukon River: implication for placer gold. Quaternary International. 2001. Vol. 82. pp. 5—32.
10. Froese D. G., Enkin R. J., Smith D. G. Placer depositional setting and their ages along Dominion Creek, Klondike area, Yukon. Yukon Exploration and Geology. Yukon, Indian and Northern Affairs Canada. 2001. pp. 159—169.
11. Levson V. M., Blyth H. Formation and preservation of Tertiary to Pleistocene fluvial gold placer in Northern British Columbia. Quaternary International. 2001. Vol. 82. pp. 33—50.
12. Lowey G. W. The origin and evolution of the Klondike goldfields. Ore Geology Review. 2006. Vol. 28. pp. 431—450.
13. Romero F. M., Canet C., Soto N. at al. The role of cassiterite controlling arsenic mobility in an abandoned stanniferous tailings impoundment at Llallagua, Bolivia. The Science of the Total Environment. 2014. Vol. 481. no. 1. pp. 100—107.
14. Torres-Hernandez J. R., Aguillon-Robles A., Siebe-Grabach C. at al. Geochronology and geochemical characteristics of a set of tertiary rhyolitic domes in the San Luis Potosi. Boletin de la Sociedad Geologica Mexicana. 2014. Vol. 66, no. 1. pp. 183—197.
15. Yao Y., Chen J., Lu J. at al. Geology and genesis of the hehuaping magnesian skarn-type cassiteritesulfide deposit, Hunan province, Southern China. Ore Geology Reviews. 2014. Vol. 58. no. 3. pp. 163—184.
16. Xie L., Wang R., Chen J. A tin-mineralized topaz rhyolite dike with coeval topaz granite enclaves at qiguling in the Qitianling tin district, Southern China. Lithos. 2013. Vol. 170—171. pp. 252—268.