Got a Eweadn mechanical keyboard and I really like it. After months of use, however, this greenish teal/turquoise stuff accummulates on the keys I use the most. It also accumulates on the sides of the keys, and it doesn't clean off easily. It seems to originate between the circular cap and the rose-gold plated rims. What is?
I apologize if this isnt the correct community to post this in, i couldnt find a generic 'what is it' community.
That's definitely brass/copper corrosion. Probably brought on by exposure to moisture and whatever else your fingers leave behind on the surface.
From what I see the manufacturer's website claims that they're "electroplated" but does not go as far as to specify that they are actually gold. So, are you sure about that? The plating is probably brass, or certainly at least contains copper.