Capgaronnite is extremely light-sensitive. There was a reasonable area of yellow-green capgaronnite after being lightly rubbed on the specimen photographed. But this had almost completely turned black by the time the photograph was taken. If you look really closely, you can just make out a small area of greenish material (indicated by the green arrow on the closeup photo). This colour change is also reversible. Ex Bernie and Margaret Day Collection. Width of view 5mm. Stack of 30 images.
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