Oshima (Wakayama Pref.) Rhyolite:  Field width = 8.8mm A caption is in the bottom. The Image is XPL on mouse to PPL
紀伊大島の流紋岩　横幅8.8mm．写真の下に説明．薄片写真：クロスポーラー（XPL)．マウスを乗せるとオープンポーラー（PPL)．

Under PPL; light green and under XPL; yellow to light green are hornblendes. Grey phenocrysts are mainly plagioclases and some are quartz.   
PPLの元で淡緑色，XPLで黄色から緑を帯びるのが角閃石．灰色の斑晶は多くは斜長石で，石英も一部含まれる．

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