The world of coins is full of collectors and students. Some people primarily collect coins. Others focus on studying them. Still others do a bit of both........... https://coins.thefuntimesguide.com/numismatist/
Some of us switch back and forth between them, too. I still save nickels and copper cents out of my change, just out of compulsion, without paying much attention to them. But I'm also gearing up to do a little bit of coin-related chemistry work, which doesn't have much to do with collecting (as in accumulating more coins) at all.
From age 8 to age 54, I was a collector. Now I am 100% numismatist. I'm 63 now and every piece I acquire other than "set maintenance" needs to have a story behind it that I wish to explore.
THIS I can hardly wait for. I got a nasty note from my landlord's "rental babe" the last time I did some "chemistry" in the ol' loft dude-cave. I don't get it; the cats were fine with it.
Difference between a collector and a numismatist? Well, I am a rabid hobbyist. I know my way around the coin world. Educated? No, not so much. The guys I see on here that will look at a persons coin photo and rattle off which obverse and reverse die varieties, the years mintage numbers and such.... Those guys are the numismatists. I wish I had the kind of time to devote to such studies. Until then, I reckon I'll just keep buying the pretty silver and gold things. I like em.....
It's old territory for you (and, for that matter, your fault). Santa brought me: The more exciting stuff, like heating in hydrogen or another reducing atmosphere, will have to wait. Possibly forever.
For future reference, you don't need reagent grade, especially in the thiourea. Too costly, not needed. Get the cheapest grade.
Factoring in quantity, shipping and such, this was the cheapest option. I wasn't sure a couple of ounces would end up being enough, and I didn't want the 110-pound drum.
My original source was Eastman Kodak, but that option went away. I usually buy either 1 pound (500g) or 5 pound (2500g) bottles.
This was 500g for $25.60, shipped from Amazon. I imagine it'll be a long time before I need to buy more, but if you've got a cheaper source, I'd love to add it to my list.