Description Augitic trachyte from Royal Sound. Small grouped crystals of augite, imitating as a whole the form of a hornblende crystal, whose place they fill. This replacement of hornblende by augite has been accompanied by the formation of numerous grains of magnetite, and in the centre of the group of augites a small brownish pleochroic remnant of hornblende may be seen. Usually, as in the drawing, this mineral has quite gone, zeolites filling the interstices between the augite microliths. 1/35 crossed nicols.
Plaats: Kerguelen IslandAuthor Anoniem in Renard (1888)JPG file - 704.44 kB - 891 x 1 324 pixelsadded on 2012-07-16555 viewsFrom reference Renard, A. (1888). Report on the rock specimens collected... (page 136) This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License