Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-27T06:41:13.971Z Has data issue: false hasContentIssue false
  • English
  • Français

Non-equilibrium highly anisometric crystals and whiskers of galena

Published online by Cambridge University Press:  05 July 2018

I. K. Bonev
I. K. Bonev*
Affiliation:
Geological Institue, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
Get access Rights & Permissions [Opens in a new window]

Abstract

Unusual irregular galena crystals and whiskers were found in close proximity in some druse cavities from the Gradishtc hydrothcrmal lead-zinc deposit in the Madan ore district, Bulgaria. The following crystal forms were observed: (1) straight thin [110] whiskers and thicker needles; (2) kinked whiskers; (3) curvilinear whiskers; (4) complex tortuous whiskers composed of segments with varying directions—[110], [100], [211], (5) thicker irregular elongated crystals. Combinations of these forms occur also. The detailed SEM study shows that all these formations are single crystals of extreme anisometricity, bounded by octahedral and cubic faces as well as by stepped surfaces of these forms. Surface structures such as longitudinal grooves, jagged edges, striations, pits, etc., are abundant.

It is assumed that these highly non-equilibrium crystals with large surface areas were formed through rapid directed growth from highly supersaturated solutions under a diffusional regime. Such special environments arose in the ore veins as a result of tectonic shocks leading locally to a drastic volume increase and P and T decrease in the solutions.

Keywords

galenacrystal morphologycrystal growthwhiskersMadan ore district
Type
Mineralogy
Information
Mineralogical Magazine , Volume 57 , Issue 387 , June 1993 , pp. 231 - 240
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bogdanova, R. and Bogdanov, K. (1986) Galena whiskers from Djalta lead-zinc deposit, Northern Tunisia. In Morphology and Phase Equilibria of Minerals, Proc. 13th IMA General Meeting (Minčeva-Stefanova J. et al., eds.). Bulgarian Academy of Sciences, Sofia, 145-51.Google Scholar
Bonev, I. (1970) Natural galena whiskers. J. Crystal Growth, 7, 209–14.Google Scholar
Bonev, I. (1980) Crystal morphology of galena from the Central Rhodopes lead-zinc deposits. I. Growth forms. Geologica Balcanica, 10, 33–56.(in Russian).Google Scholar
Bonev, I. (1984) Mechanisms of the hydrothermal ore deposition in the Madan lead-zinc deposits, Central Rhodopes, Bulgaria. In Proc. 6th IAGOD Symp. Schweizerb. Verlagsb., Stuttgart, 69-73.Google Scholar
Bonev, I. (1990) Whisker growth of minerals. 15th IMA General Meeting, Beifing. Abstracts, 1, 382-4.Google Scholar
Bonev, I. and Radulova, A. S. (1991) Chalcopyrite whiskers. Neues. Yahrb. Mineral. Mh., 559-68.Google Scholar
Bonev, I. Reiche, M., and Marinov, M. (1985) Morphology, perfection and growth of natural pyrite whiskers and thin platelets. Phys. Chem. Minerals, 12, 223–32.Google Scholar
Chernov, A. A. (1983). Processes of crystallization. In Modern Crystallography (Veinstein, B. K., ed.), 3, Nauka, Moscow, 7-232 (in Russian).Google Scholar
Guo, W., Ning, X. G., Zhu, J., and Ye, H. W. (1990) Growth morphology of titanium nitride whiskers. J. Crystal Growth, 106, 400–404.Google Scholar
Holland, H. D. and Malinin, S. D. (1979) The solubility and occurrence of non-ore minerals. In Geochemistry of Hydrothermal Ore Deposits (Barnes, H. L., ed.) 2nd Edition. Wiley, New York, 461–508. Google Scholar
Kern, R. (1987) The equilibrium form of a crystal. In Morphology of Crystals (Sunagawa, 1., ed.), Pt. A. Terra, Tokyo, 77-206.Google Scholar
Kostov, I. and Minčeva-Stefanova, J. (1981) Sulphide Minerals. Crystal Chemistry, Parageneses and Sys-tematics. Bulgarian Academy of Sciences, Sofia.Google Scholar
Kristotakis, K. (1979) Der Einfluβ der Löslichkeit auf die hydrothermale Mobilisation des Baryts. Neues Jahrb Mineral. Abh., 135, 132–47.Google Scholar
Maleev, M. N. (1971) Properties and Genesis of Natural Filamentary Crystals and Their Aggregates. Nauka, Moscow (in Russian).Google Scholar
Mansour, S. and Scholz, R. (1990) Characterization and growth of lead sulfide whiskers. Mater. Letters, 9, 511–6.Google Scholar
Minčeva-Stefanova, J. and Gorova, M. (1965). Minera-logic und Geochemie der Blei-Zink-Lagerstatte Gradiste in Erzbezirk Madan. Tray. Geol. Bulgarie, Serie Geochim., Mineral, Petrogr., 5, 117–91.Google Scholar
Sangwal, K. (1987) Etching of Crystals. Theory, Experiment and Application. North-Holland, Amsterdam.Google Scholar
Takeuchi, Y. (1978) ‘Tropochemical twinning': a mechanism of building complex structures. Rec. Progr. Natural Sci., Japan, 3, 153-62.Google Scholar
Trufanov, V. N., Kurshev, S. A., Maysky, J. G., and Ushak, A. T. (1986) Crystal growth under high temperature and pressure gradients. In Morphology and Phase Equilibria of Minerals. Proc. 13th IMA General Meeting (Minéeva-Stefanova, J., et al., eds.). Bulgarian Academy of Sciences, Sofia, 119-24.Google Scholar
Tufar, W., Gundlach, H. and Marchig, V. (1984) Zur Erzparagenese rezenter Sulfid-Vorkommen aus der siidlichen Pazific. Mitt. Osterr. Geol. Ges., 77, 184–245.Google Scholar
Veblen, D. R. and Post, J. E. (1983) A TEM study of fibrous cuprite (chalcotrichite): microstructures and growth mechanisms. Amer. Mineral., 68, 790–803.Google Scholar