Gadolinium is shiny, Europium is dull

I’m playing with my new rare-earth element sample set, and loving it. The rare-earth set came in a nice wood base with cover. I bought it from Metallium Inc., for $125, and it arrived a few days ago.

The rare-earth elements — the 17 elements encompassing scandium (21), yttrium (39), and lanthanum (57) through lutetium (71) — are fascinating, both historically and chemically. I have several interesting element and mineral samples on my desk, including a large ingot of metallic silicon that I got in Nevada. But the rare-earth element set is my favorite.

The set contains sealed samples of all the rare-earth elements (except for promethium, of course). The samples weigh between .5 and 1 grams, and the glass ampules are vacuum filled. The photo is of my set, without the clear cover. (Click the picture to enlarge.)

I’m very impressed with the Metallium folks. They shipped out the set in just a few days, and it was well-designed and well-packed. The metal samples look great. I can enthusiastically recommend buying from them.

On the Metallium Web site, they show a set of time-lapse photos showing what happens if you expose the rare-earth elements to air. They start out looking nice. After four days, europium is visibly starting to corrode, and it’s gone in a month. After a couple of weeks, lanthanum is looking sad. They kept the experiment running for four years. Check it out…

I’m definitely going to purchase more from Metallium. What should it be: the 46 “coins” stamped from pure elemental metals? Some half-inch rods? A chunk of osmium? How about the 76-element set?