About authigenic nature of small cassiterite pebbles in alluvial placers of Chukotka
I. V. Tibilov, S. N. Bocharov, A. E. Glikin, A. A. Antonov, Yu. V. Plotkina.
Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2015. V. 144. N 1. P. 122-133
Studied features of internal structure and the surface relief of small cassiterite pebbles from placer deposits of Chukotka proves their authigenic nature. Small pebbles are in fact composed of single metasomatic cassiterite crystals of sub-spherical habit; much rarely they are also represented by metasomatic spherule-shaped aggregates of tin wood. The article discusses questions of the crystal-genesis of spherical cassiterite crystals in loose alluvial sediments.
Key words: pebbles, placer deposits, cassiterite, tin wood, spherule-shaped monocrystals, subspherical habit, zonal coloring.