Mike, those are great reproductions -- in what time frame did the Indian's start using copper hooks?
The time frame for Indian use of copper in North America generally stretches from 1700's on back before 900 or 1000 A.D. Exact dating is kind of poor because of the lack of other surviving objects that can better be dated - like coins during the Roman era. So carbon dating of other artifacts recovered at the same time/place needs to be done, and those can be off by several hundred years. The Indians were working surface collected copper nuggets - called float copper. Little or no actual "mining" took place, just working those found nuggets.
So the original artifacts all show a level of "impurities" in them. I worried about replicating Copper Culture pieces for a bit. But starting with modern refined copper makes them a whole lot easier to distinguish from original artifacts.
The hooks fit most of the Copper Culture time period. And that era mostly ended when contact/trade was established with Europeans for their iron/steel trade goods. But those European explorers were very interested in the copper deposits they found - especially those around the western end of the Great Lakes. It wasn't gold or silver, but was still a valuable resource.
So by the early 1700's, copper items had mostly been replaced with iron/steel - those fish hooks, knives, axes, awls, etc. But some of the "old stuff" continued to be used.
Working copper is different from working iron/steel. The material absorbs almost all the energy/force from a blow. You get no rebound of your hammer. So forging copper wears out your arm much faster. And you really need to watch that you do not over-heat it, or it will just melt on you. Working/hammering it cold has its own problems. All metals work-harden. When hammering copper cold, you will "feel" the copper slowly getting harder under your hammer. If you continue to work it after that, it can quickly start to crack/split on you. So you have to anneal it often. Copper and brass anneal the exact opposite from iron/steel. You heat it up till it is glowing red, then quench it in water to anneal (soften) it. To harden it, you heat it up and then let it air-cool. Just the opposite of iron/steel.
I did not file/grind/sand those items smooth - like most of the originals would have been. Just forged them to shape. So they have that ... just forged ... look to them. The national park loved them.
Mikey - that grumpy ol' German blacksmith out in the Hinterlands
) , I always said i would never make jewelery agian after i stoped 10 yrs ago but I really enjoyed making this today, I hope you like it comments always welcome.
There are times when something is just 'right', and the brooch is 
