驚豔．新視野－科學攝影事件簿 2014-2015
㼭㼭涸䃋
Mini Island 庶ꈘꆀ
茫茫的斜長石海中，出現一片猶如小小的島的黑 雲母。初時乍看土氣十足，換個角度看，竟然黯 淡無光。但只要用心點，加上一片偏振片，就能 看見動人光輝的生命力！屬於鐵鎂質礦物的黑雲 母，解理方向、輪廓相當清晰；轉動時，因為雙 折射進入黑雲母的兩道光速度不同，所以會產生 多色性的現象，黃色部分轉動後會變成黑色。當 加上偏振片之後轉動後會平行解理方向消光；另 外，亮綠色的干涉色，其顏色則和燈光有關。
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A mini island-like biotite is found among the plagioclase crystals. At first sight, it appears unrefined. Switching to another angle, it seems dim and bleak. However, the island is brought to life by the addition of a polarizing plate. Biotite, a common mafic mineral within the mica group, has a perfect cleavage with multicolor effect created by double refractions of light entering the mineral. By turning, the yellow part becomes black. After adding a polarizing plate, light disperses horizontally onto the cleavage angle. The interfering green tint is a result of the lighting effect.