Gday
Using the Xterra I have found gold jewellery which gave a tone similar to foil, ringpulls, Aussie 5c piece (small cupro-nickel coin) , 20c (medium c/n), 25c coin (large c/n coin), $1 and $2 coins.
The tone maybe broken at times, like when a ring has larger gemstones (or a thin chain), sometimes I have heard a little higher pitched "ping" as the coil moves over the edge of the target (it was a nice thick 9K gold ring) and sometimes I have heard a double tone like a shallow ring can give.
TID's also vary as widely as the above objects typically give off.
One thing I found amazing...there was a guy on here a couple of years ago from New Zealand picking up beach rings witrh TID's in minus .. -2, -4 if I recall correctly.
Both the tone and TID can vary according to shape, mass, size plus the carat of the gold (low k gold = lower tone and TID as a rule)
Soil conditions, depth, how well your machine is balanced then also come into play
so as you see and others have said there is no right or wrong answer as it just varies too much
I like to dig a variety of targets most hunts and have been sometimes rewarded by gold by doing so
Keep digging the low tones like ring pulls and the 9 or 10K will come to you

best of luck
T59
