Hawk’s eye and tiger’s eye manifestations within Kryvyi Rih basin

Authors:

V.O. Andreichak, State Higher Educational Institution “Kryvyi Rih National University”, Assistant Lecturer of the Department of Geology and Applied Mineralogy, Kriviy Rih, Ukraine.

V.D. Yevtekhov, Dr. Sci. (Geol.-Min.), Professor, State Higher Educational Institution “Kryvyi Rih National University”, Head of the Department of Geology and Applied Mineralogy, Kriviy Rih, Ukraine.

Abstract:

Purpose. To give general information on hawk’s and tiger’s eye occurrence within the Kryvyi Rih basin; to present geological description of priority objects and to determine regularities of their occurrence in the section of the Saksaganska suite; to describe stages of formation for the both varieties.

Methodology. Geological mapping using mineralogical sampling of hawk’s and tiger’s eyes occurrence and microscope studies by means of petrographic and mineragraphic microscopes have been carried out.

Findings. Occurrences of hawk’s and tiger’s eyes are found in each and every deposit of the Kryvyi Rih basin. The most frequent and sufficient mineralization occurs in the central part of the Saksaganskyi iron ore region of the Kryvyi Rih basin in Gleyuvatske deposit of low-grade magnetite ores and high-grade hematite ores of the “M.V. Frunze” Mine. The occurrence of the gems is systematic there. For some deposits in the northern and southern parts of the Saksaganskyi iron ore region as well as for the Southern, Northern and Ingultskyi iron ore regions the episodic, solitary findings of veinlet of grey, blue, dark blue hawk’s eye, sometimes of greenish-grey, cat’s eye are common. Formation of grey-colour hawk’s eye wascausedy silicitication of kummingtonite asbestos which composes Alpin interlayers of magnetite-cummingtonite (so called “law-ore”) quartzites of the seventh schistose horizon of Saksaganska suite. Hawk’s eye of blue and dark blue colours was formed in the consequence of three different geological processes, such as silicitication of parallel-fibrose aggregates of magnesioriebeckite in Alpine interlayers of magnetite-magnesioriebeckite, magnetite-cummingtonite-magnesioriebeckite quartzites of the seventh schistose horizon, silicification of parallel-fibrose aggregates of epigenetically riebeckitized initial cummingtonite-asbetos resulted from sodium metasomatosis. Cat’s eye represents siliciticated parallel-fibrose aggregates of cummingtonite, sometimes actinoliteasbestos, with an admixture of small scallychlorite crystals that givers typical greenish-grey colouring to the semiprecious stone. Tiger’s eye is a product of hypergenic changes of all colour varieties of hawk’s and cat’s eyes.

Originality. Regularities of hawk’s eye and tiger’s eye distribution within the Kryvyi Rih basin have been determined. Stages of formation of the main colour varieties of the gems have been characterized.

Practical value. The data obtained can be used for exploration of occurrences of the gems; it improves the effectiveness of the complex utilization of the Kryvyi Rih basin mineral resources base.

References:

1. Андрейчак В.О. Поширення тигрового та соколиного ока в межех Криворізького басейну: матеріали IX Всеукраїнської конференції „Сучасна геологічна наука і практика в дослідженнях студентів і молодих фахівців – 2013“ / В.О. Андрейчак, В.Д. Євтєхов – 2013. – С. 81–84.

Andreichak, V.O. and Yevtekhov, V.D., (2013), “Tiger’s and hawk’s eyes occurrence within Kryvyi Rih basin”, Proc. of the 10th All-Ukrainian Conference “Modern Geological Science and Practice in Students’ and Young Specialists’ Researches – 2013”, pp. 81–84.

2. Блоха В.Д. О поделочных камнях Кривбасса / В.Д. Блоха // Відомості Академії гірничих наук України. – 1997.– №4. – С. 45–46.

Blokha, V.D. (1997), “Concerning ornamental stones of Kryvbass”, Vidomosti Academii Hirnychykh Nauk Ukrainy, no.4, pp. 45–46.

3. Минералогические особенности кварцевого кошачьего глаза из Криворожских железорудных месторождений / В. Хефлик, П.Н. Баранов, Л. Натканец-Новак [и др.] // Науковий вісник НГУ. – 2008 – №8. – С. 68–72.46

Kheflyk, V., Baranov, P.N. and Natkanets-Novak, L. (2008), “Mineralogical peculiarities of quartz cat eye from Kryvyi Rih iron ore deposits”, Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, no.8, pp. 68–72.

4. Баранов П.Н. Гемологія: діагностика, дизайн, оброблення, оцінювання самоцвітів / Баранов П.Н. – Дніпропетровськ: Метал, 2002. – 208 с.

Baranov P.N., Gemology: diagnostics, design, treatment, gem evaluation // Dnipropetrovsk: Metal, 2002. – 208p.;

5. Стоун Дж. Все о драгоценных камнях / Стоун Дж. – М.: Оникс, 2004. – 175 с.

Stone J. All about gemstones // Moscow: Onyx, 2004. – 175 p.

2015_02_andreichak
2015-10-10  2.07 MB  1046