First off, these earrings are incredibly beautiful! The opals are just stunning.
However, after owning them for a few months- and wearing them about 10 times- I've noticed that the backings seem to have oxidized, leaving a blue-green tinge in the rubber backings. I thankfulky have extra backings, but it was surprising to see. For reference this is just from everyday use, I did not shower with them and they were stored in a jewelry box between wears.