Introductory Views of Current Electron Microscopy for Clay Minerals

Abstract

Recent technological developments of the transmission electron microscope (TEM) including an analytical TEM are briefly reviewed with the principles for image formation by objective lens and chemical analysis by EXD and EELS.
New developments are mainly made for clean and high vaccum and easy use by CPU. Namely, clean and high vaccum made it possible to use LaB₆ electron gun, convergent beam electron diffraction, reflection electron microscopy, electron energy loss spectroscopy, and so on. Computer control systems are also realized not only for analytical purposes but also for high resolution observation.
In the last section, the alteration process of pyroxene to clay minerals is described as an application of high resolution TEM observation. Augite from a gabbro in the Horoman ultramafic body, Hokkaido, has been found to be altered to double-chain, triple-chain, and more highly polymelized multiple-chain pyriboles and finally to clay minerals.