Moderockルテニウム金属元素周期表、ミラー仕上げの密度キューブコレクション、純度99.95%、重量11.5g/0.39オンス(Ru Cubic 10mm/0.39インチ)

Rhenium has a beautiful, shiny luster, and is also very tough, and scratch resistant (only tungsten and chromium are harder). It is one of the densest metals (more so than tungsten), so you'll want to hold it in your hand to feel the heft. And good news; your skin oils won't tarnish it at all, just wipe the mirror-finish clean with a soft cloth. I was very pleased with the high quality. The packaging was generous, and arrives in a somewhat comically-oversized tin box, and nested inside round screw-cap container within (as pictured in the listing). Shipping took about 2 weeks.