Original paper

Re-examination of kochelite: A mixture of metamict fergusonite-(Y) and altered zircon

Janeczek, Janusz


Kochelite, first described by Websky in 1868 as a new mineral from pegmatite in the Karkonosze granite, SW Poland was considered a product or products of alteration of Zr-rich fergusonite. An investigation of a topotype sample by optical microscopy, back scattered electrons imaging and electron microprobe analysis show that the name kochelite was applied to an artificial mixture of metamict fergusonite and chemically altered partially metamict zircon. A complex pattern of chemical alteration in both fergusonite and zircon occurred due to the action of alkaline hydrothermal solution during albitization of K-feldspars. The second stage of alteration was related to the weathering of the pegmatite.