Thursday, April 24, 2014

Gold Test

I changed the bait to gold on the L-rod and spent a further four hours detecting on the same field as the Silver Test (see previous post). The photo illustrates the finds. The first three objects from the left on the top row all have some gold plating remaining, while the fourth object is silver plated copper-alloy. The remaining finds are all copper-alloy. There was also some junk in the form of iron and aluminium although this was minimal.

Now I admit this is not a very scientific test because every time a find is removed from the ground, the conditions of the experiment are changed. You can see this in that the number of finds in the gold test was only a third of the number found in the silver test, for the same amount of detecting time. The law of diminishing returns in action! What is significant though is that in both the silver test and the gold test around one quarter of the finds contained the metal used for bait. If that continues in the field then, I am sure you will agree it must make a big difference to treasure hunting success…

Wednesday, April 16, 2014

Silver Test

I had a small pasture field available, which I had searched in the past and made very few finds. The field had just been mown so searching conditions were as good as they could be and I decided to use the field as a test site for natural finds. I was now using a Detech EDS metal detector, fitted with 12 inch SEF coil, which I had not used on this field before. I baited the rod (see Trust the Greeks, especially when they bear gifts) with silver and used the rod in one hand and my detector in the other, the principle being that the rod guides the detector to the finds. Bear in mind that the brass (copper-zinc alloy), which the rod is made from, forms the largest sample or bait by far, so the rod will naturally find copper alloys and should also find silver because of the added silver bait. There may also be chance finds that you just happen to walk over.

The photo shows the finds made after a four hour search (plus there were three lead objects that I couldn’t fit into the photo). The top row of seven objects all have some silver content (the two George V sixpences are 50% silver) and it is likely that the old lead objects contain traces of silver as an impurity. The rest of the coins and artefacts in the photo are copper-alloy. There was also some junk in the form of iron and aluminium although this was minimal.

Next time, I’ll perform a field test using gold bait…