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Steve Herschbach

Target ID / VDI Numbers For Gold Nuggets And Gold Jewelry

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On ‎4‎/‎25‎/‎2017 at 11:05 PM, Steve Herschbach said:

Here is the final thought for the night. Back when Fisher did the CZ series of detectors they did lots of ring testing. They tested 255 rings for the CZ-70 and came up with some interesting percentages. I have seen these percentages reflected in the field.

2% of the rings were in the copper penny, dime, quarter range.

4% of the rings were in the zinc penny/screw cap range

49% of the rings were in the "pull tab" range above U.S. nickel

10% of the rings were in the nickel range

36% of the rings were in the foil range below nickel

0% of the rings were in the iron range

Now look at my simplified X-Terra VDI chart in the post immediately above. What we are seeing is the difference between women's rings and men's rings. Women's rings tend to be small high quality rings, and cluster in the foil range. They are the rings most likely to have stones and be of high value. Men's rings are significantly larger and heavier, and fall into the area above U.S. nickel. There is a weak spot or gap between women's and men's rings in the nickel range. This is of course a gross generality but I have found it to be true in my own detecting. You can use this to good effect when looking at an area and deciding what might be found there. Is the area more likely to hold men's rings and women's rings? The football field will more likely have men's rings. The shallow childs wading area or tot lot will lean women's rings. I do a lot of heavy surf detecting, and nearly all my finds are men's rings.

I have mentioned the Fisher CZ detectors. Rumor has it that CZ stood for "Coin Zapper". The CZ detector are unique in having a shuffled discrimination scale that puts nickels up high with the other coins. Little attention is paid to the fact they also lumped the bulk of the ring zones together. In addition to visual target identification, the CZ  has 3-tone, audio target ID. A low tone is for iron, a medium tone Is for pull tabs and foil and a high tone is for coins. A fourth tone, which sounds like a telephone, alerts you to large, shallow targets that are usually (but not always!) trash.

Basically with a CZ, low tone is iron, medium tone the ring range, and high tone the coin range. The newest model, the CZ-3D adds a fourth tone to the scheme designed to capture old coins in the zinc penny range, but for jewelry detecting the original CZ scheme is pretty simple and ingenious.

The good news is with newer detectors that have custom tone id ranges you can duplicate this setup yourself. Fisher also offers this modified tone scheme in the F75 models. The main thing is to be aware, no matter what detector you are using, or where the possible ring "hot spots" are on the VDI scale depending on where you are hunting.

From Fisher CZ-70 Pro Owners Manual, page 24 (tones added):

fisher-cz-7a-pro-ring-percentages-chart.jpg

 

This is fascinating stuff.  Interestingly enough, I dug 6 gold rings last year.  A solitaire, 3 bands, and 2 child's rings.  The solitaire fell in the nickel range, the 3 bands were all in the zinc penny range, and the two child's rings were down in foil range (both tot lot finds).   Based on the percentages above...aside from the "dig it all" tot lot finds.... I walked over 25 gold rings.  And I believe those statistics.  

It is a lot of work to commit to the mid tones... but it is obvious that is where the yellow is.  

Tim.

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I always try and keep the VDi's that could be jewelry active because if you don't dig it you don't find it. 

I dig a lot of foil and it's surprising how small of a piece of foil I detect and that only tells me if it were jewelry I would find it. I most often find jewelry in tot lots and sidelines of ball fields.

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