False Positives?

The 3-S Rule
Here's an old time-tested process to help you sort out trash from treasure. It's the 3-S rule, and goes as follows:

3-S is Sound, Shape and Size. Let's say you are hunting for coins and jewelry ....

If your target Sounds like a coin / ring - EG: Tone ID, Repeatable target, No Threshold drop (iron) then it passes the SOUND "S".

If your target is "the same Shape" from all angles when you pinpoint (a circle is the only shape that fits this criteria), then it is probably a "round" target, which is a coin / ring. You have passed the SHAPE "S".

If your target is less than a couple inches in width, then its probably a coin. You have passed the SIZE "S".

If you run across a target that VDI's like silver or a ring, but it's oblong, or its 4" wide or if the threshold drops out, you probably don't have a good target - EG: not a ring or coin. Its up to your experience at that point whether to "pass or dig". I always recommend - "when in doubt - dig". You COULD have a good target being masked by trash.

Hope this is helpful.

Above shamelessly borrowed from the Whites MD site.

That's good advice. I've dug a few coins now and feel like I definitely know the shape and size of one. I always x it over and make sure its consistent from all angles, etc. I probably still need work on the sound bit. If I were on an old piece of property I would have definitely gone deeper, but the house was built in the 80's and I guess my imagination didn't entice me enough to continue trying to chisel through the hard layer of clay. I may have to go home and break out the dynamite though...

If I was getting a small, coin size signal I would be tempted to dig it...but usually I'm getting a very strong, large signal deeper than 6-8" and I pass on those because it would have to be a large piece of trash (a can usually) to signal like that. 'course it COULD be a jar of gold coins......................