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When I look at a glass block at an angle the edges appear green, but when I look at the edge sideways, so that is directly in front of my eyes it appears transparent. Why?

Chryron
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1 Answers1

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Most glass contains iron oxide as an impurity which gives the glass a slightly green hue. When you're looking straight through a pane of glass you don't notice it because the glass is so thin. But when you look down the side it becomes apparent because of the thickness.

lemon
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