I have been an off-and-on chemistry hobbyist for years, and I have always wanted an element collection, but since I collect lots of stuff I haven't gotten serious about it until recently. A search led me to this thread.
Here is what I have so far, along with where I got it.
Mercury, Sulfur, and Sodium - from the local chemical shop.
Copper - from a science gift shop and in coin form.
Strontium, Indium, Manganese, Iron, Antimony, Nickel (also in coin form), and Bismuth - a friend gave me these; they came from some discarded chemicals.
Silver, Zinc, Aluminum, Platinum, and Gold - in coin form. I plan on eventually getting these in other forms.
I have recently done some searching on the web, and it looks like a lot is available, but some are rather difficult. So far, I have been unable to locate lithium (I'm surprised at this - I would think that it would be everywhere), rubidium, cesium, barium, phosphorus (red or black - I don't want white!), arsenic, fluorine, chlorine, and bromine from sources that will sell to individuals in the United States. (Of course, most of the radioactive elements are impossible to obtain. Uranium ore will have to cover many of them.) Some of these (especially the halogens) are quite dangerous and I would only want them in tiny quantities in tightly sealed containers. I know how to make chlorine and bromine, but I'm not really sure that I want to take the risk; I would rather buy them. Bromine is infamous for its ability to escape from containers anyway, and I don't want it floating around in the air. Maybe I should satisfy myself with compounds for the dangerous halogens.
Probably next on my list will be the rare earths. They are reasonably easy to find and not too expensive, and they aren't terribly dangerous. Many eBay sellers have them, and United Nuclear has a rare earth sample set.
So has anyone here found samples of the difficult ones (or others like them that I may have forgotten to mention)?
I'll have to look around this site and see what else is here. Getting into this element collection is rekindling my interest in chemistry. Perhaps it is time to start playing with chemicals again.