A Detectorist is someone who uses a metal detector.
Per Coin World, one detectorist in Waco, Texas found a "base bar" from a minor gold rush era California assayer. A base bar is an ingot of "naturally occurring ore" that is melted and weighed into a convenient size for transport. The bar is 82% copper, 14% silver and 1% gold. Balance is misc junk.
Stamped on it is:
No. 8824
Huhn and Luckhardt
N.M.W (Nevada Metallurgical Works)
San Francisco
OZ: 25.4
G. (gold) 007.3 F. (fine)
S. (silver) 148 F.
G. (gold) $3.81
S. (silver) $4.86
$8.67
Per Coin World, another detectorist found a "George II medal" in Massachusetts.
They think it's a "peace medal" given to and Indian chief. Made of lead and has a portrait of King George II (1760) of England on it. It's holed at the top and is uniface (no design on back). There's a similar medal in the British Museum.
Found on a friend's land. The detectorist also claims to have found a "$30,000 ring" he sold through Sotheby's and several French and Indian War (1750s) and Revolutionary War era items.
Cool!
If you haven't already, I recommend going to the British Museum website.