Actually the Compass au52 was the one that was used. And tiny nugget was 4 1/2 inches inside the quartz. And yes the nugget was about the size of a pinhead. My Compass R&C commonly finds #8 lead shot at 6" in high iron soil. The eliptical coil will find it about an inch deeper though, if you are lucky enough to ever find one of those for sale.
So far, not even the Fisher GB2 can quite match the tiny nugget depth of the old Compass gold nugget hunters (au52, au2000, GoldScanner Pro, and Relic & Coin) in [high iron] soil, and neither can any other detector, including White's, Fisher, Tesoro and Minelabs. Sometimes people CLAIM they can, but that's just a lot of smoke and no fire - because they can only do it in "test beds", lightly mineralized soil that has been disturbed by moving it from one place to another.
I have done all the one-on-ones matching all kinds of detectors against the old Compasses, and so far in real life it's been all smoke and no fire. Compasses are STILL the kings of small item finders.
Remember folks, that according to ALL current and past detector engineers (myself included), it is nearly impossible to find something other than iron deeper in the ground than it does in the air, save for copper in very rare instances, or lead and bronze, brass, in even rarer cases.
Sometimes older is still better.
LL