Caledonia Copper Mining Co. ID Tag

They are also called in and out tags, Since the more common practice was to have two boards with nails in them and they were labeled in the mine and out of. At a glance they could tell how many were in the mine. This was important when they were going to doing blasting in the mine. There would be a log book with the employees names number and name.
The same tags were also used with with the employees number as tool id tags and also for tool checks employees would give a check when they would need to check a tool out for use.
Another use was for explosive and detonator checks, miners had to pay for what they used on payday. they used the checks to keep track of the amount. This help the theft of explosives down and also encouraged the efficient use of the powder and detonators. They would have a number of sticks or pounds of powder or number of detonators on them.
Yours are nicer than most because it has the mining company name on them. Most were made in the mines workshop out of brass sheet,disks, or aluminum scrap. A to value they aren't rare, Most shop made ones are in the $3.00to $20.00 range. the ones with the mines name etc. are in the $20.00 to $30.00 range .
A word of caution there are a lot of fakes out there. Mostly in the tourist mining areas and on auction sites make sure they are well documented before paying the bog bucks

The repro's generally go for higher prices and the pump up the story from famous mines that had a disaster of famous for other reasons. A very nice token here you go Years ago I have worked the waste rock piles collecting native copper and other mineral.

Here are a couple of pieces from the waste dump picking
https://www.mindat.org/loc-9510.html link to the mine info

Yep Up in yoppers country In the U.P. here is some history http://www.exploringthenorth.com/ca...history.html Welsh and Scandinavian miners and home of that fine miners lunch pail delight. The pasty which in fact we had for dinner last night.