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3 hits

  • Thumbnail for AGUNG PMC

    The high quantity of vesicles in this thin section keep the phenocrysts of plagioclase, clinopyroxene, and olivine well separated. While the clinopyroxene is euhedral in shape, the other two phases are more subhedral. Plagioclase phenocrysts have a sieve texture. The groundmass is mostly glass, with a few, moderately sized grains of plagioclase.

  • Thumbnail for JPN-4

    Vesicles and a glassy matrix containing tiny plagioclase microlites separate this scoria's partially fragmental, partially resorbed, sometime poikilitic, sometimes glomeroporphyroclastic phenocrysts of plagioclase and pyroxenes.

  • Thumbnail for BATUR 1936
    BATUR 1936

    Subhedral phenocrysts of plagioclase, clinopyroxene, and olivine are squeezed into the fine web of rock that rims the massive vesicles of this scoria. Plagioclase has a sieve texture and is frequently zoned. The corners of most grains are rounded. Both clinopyroxene and olivine are generally equant in shape and olivine is more abundant than the pyroxene. All three phases show some degree of resorption. The groundmass contains moderately-sized crystals of all three phases. This sample is very fresh and unaltered.