Looking on the Rozen Maiden Wikia for the Rozen Maidens, I notice they all have titles
- Suigintou = Mercury Lamp
- Shinku = Pure Ruby
- Hinaichigo = Small Berry
- Suiseiseki = Jade Stone
- Souseiseki = Lapislazuli Stone
- Barasuishou = Rose Crystal
- Kirakishou = Snow Crystal
- Kanaria = Canary Bird
i get most of them are either a trait they have (Hinaichigo is small, Barasuishou attacks with crystals) or their primary color scheme (Kirakishou is white like snow, Kanaria is yellow like the general depiction of a canary).
But I don't understand why Suigintou has the title of Mercury Lamp. From my understanding, Suigintou's color scheme is black (2013 anime) or purple (2004 anime) while Mercury as the metal is silver, while I don't think the planet is black or purple. Nor do I get how Lamp fits.
So how does Suigintou's title match with her?