Goldsmith
Compared to other metals, gold is malleable, ductile, rare, and it is the only solid metallic element with a yellow color. It may easily be melted, fused, and cast without the problems of oxides and gas that are problematic with other metals such as bronzes, for example. It is fairly easy to "pressure weld", wherein similarly to clay two small pieces may be pounded together to make one larger piece. Gold is classified as a noble metal—because it does not react with most elements. It usually is found in its native form, lasting indefinitely without oxidization and tarnishing.
Thulium
Thulium is the second-least abundant of the lanthanides, after radioactively unstable promethium which is only found in trace quantities on Earth. It is an easily workable metal with a bright silvery-gray luster. It is fairly soft and slowly tarnishes in air. Despite its high price and rarity, thulium is used as the radiation source in portable X-ray devices, and in some solid-state lasers. It has no significant biological role and is not particularly toxic.