I don't know about Lexington, but there's plenty of gold to be found around Mc Cormick. The problem is its all private property with posted signs. See if you can find a navigable waterway around there, and you should be ok to do some prospecting on it.
I've not looked in Lexington, but my fiancee' is from there and I'd like to check some creeks down that way,,,around the Swansea area...I live in Troy about 8 miles East of McCormick, in Greenwood County...I've found placer gold in three different creeks...It's still a mystery to me, the way it is in the creeks...I'm finding more in the sands going down to the bedrock, than I am at the bedrock... Astrobouncer has what I think is the best/right explanation....That is that the old timers got the good stuff off the bedrock back in the day, and what I'm finding in the sands is "new" gold! There are old gold mine "pit" all over the place down here on National Forest Lands,,,Be careful around them, they go from very shallow (indention's in the ground) to very deep! I know 1 in McCormick County on National Forest that is at least 75 feet deep!! It at one time had a fence around it, but it is rotted out and you have to look close to tell that there was a fence there at one time. Another word of caution; When the pits were dug the old timers piled the quartz up on the side of the pits, they are still there, if it's warm weather watch out for snakes!! Perfect place for an ole copperhead, or twelve!!
Brooklyn, if NC has a dept of mines and geology or call BLM and ask for a mine or minerals report. It should list all areas in NC where gold was found. I believe gold was first found in NC. so yes you are good to go for places to hunt for gold there.