Vintage Enamel Pin “RU” Robin’s Egg Blue Silver Logo

This pin was part of an estate purchase and I’m not sure what this pin represents, maybe a logo? Or someone’s initials? Maybe your initials are RU and you would like a cool personalized pin, or you’re a chemistry nerd and fond of ruthenium and want to represent. Or maybe you just really love this shade of robin’s egg blue and want people to ask you what RU stands for. Some minor use wear, no major flaws that I can find. Please see images for details.