多形态自然硒的首次发现及其成因初探

在湖北省恩施市渔塘坝的富硒碳质硅质岩、碳质页岩及其废弃岩中堆中，作者首次发现了多种形态的自然硒。本文根据自然硒的产出环境和成因将其分为三种，一种产于近地表废弃“石煤”堆中；一种与构造作用有关；另一种与表生风化作用有关。近地表废弃“石煤”堆中的自然硒是与岩层（或自燃）有关，见有晶形完好、颗粒粗大的晶体；与构造作用有关的自然硒多为毛发状、针状；与表生风化作用有关的自然硒颗粒细小，针状晶体少见。

SOME NEW FORMS OF NATIVE SELENIUM AND THEIR GENETIC INVESTIGATION

In the Yutangba of Enshi City, Hubei Province, China, we have discovered native selenium, which varies morphologically due to different mechan isms. One kind of native selenium, which is good in crystal morphology and larg er than other species in grain size, is produced by crystallization of selenium gas due to natural burning of discarded !stone-coal" under some special condit ions. This kind of crystal line selenium has been reported in previous literatur e. The other two kinds of native selenium in regard to supergene weathering and tectonic activity process are still studied at present. Crystals of selenium for med by natural burning of Se-rich rocks (carbonaceous siliceous rock and carbon aceous shale) seem to be the result of firing by local villagers.