Perthite from an Antarctic granulite

The image shows the perthitic microtexture in an alkali feldspar from a granulite from the Brattstrand Bluffs, East Antarctica. The sample has been etched in HF acid vapour to reveal the microtexture. The image shows both rounded 'blebs' and fine elongate lamellae of plagioclase wihin a K-feldspar host.

The image represents an area approximately 15 µm wide.

Image courtesy of Dr. Nicola Cayzer,

Geology and Geophysics, University of Edinburgh.