I've always had a liking for oxidized lead, or thallium, the take on a dark, lead-ish (for want of a better term) hue, that really is quite attractive, once it has had time to oxidize and form a surface layer, rather than look like shiny, freshly cast metal. That dark color and soft texture combined, there is just something nice about it, despite the toxicity. The way old lead bends like wire, so soft, almost like cutting sodium with a knife, and that dark, almost decaying hue, its great looking despite the toxicity of either lead or thallium.