Praseodymium is a lanthanide with the unusual ability to have a +5 oxidation state. Though it generally is happy with just forming +3 oxides. Pure praseodymium will develop a lovely green shaded +3 oxide on its outside given time. It is one of the most useful lanthanides, used in everything from optics to magnets, lights, construction, catalysts, aircraft engines and even has helped get us the ability to chill things down to within a few thousandths of a degree of zero. It was hiding in plain sight for many years, often being confused with silver due to its very similar lustre and hardness. There is no doubt that some ancient silver vessels probably have some praseodymium in them.
Iguana makes a good match for praseodymium as they both tend to form the same green and tend to hide in plain sight and are surprisingly useful.
“Neodymium will make lovely glass.” As the song goes. Ok maybe only I heard that song. Or made it up? Neodymium is also a non-rare “rare earth metal” being no rarer than no rarer that cobolt, nickle or copper. It is, as you probebly guessed mostly used to make glass in a verity of colors, especially blues and pinks. It is also used in ceramics. The existance of neodymium will possibly help us achive fusion power in years, from its us in high powered lasers.
Crows are where the name Corvid comes from. They are one of the most talented birds, being able to form patterns and predict how things will happen. Some crows have been seen picking up nuts they have cracked using cars on pedestrian crossings. Others have used the same tactics to help kill prey. It’s tied with Neodymium as they are both exceptional.