Monday, December 6, 2010

12/6 Report - Acid Testing & Beach Combing

Two Plain Silver Rings Found on Treasure Coast Shipwreck Beaches.

These are the type of thing that are very difficult to identify - not much of a design to go by and no markings. The only thing to suggest that they might be from a shipwreck is the location where they were found.

There are metallurgical procedures that can help tell where the metal in the object came from, but other than that, it is very difficult to say.

It seems there was a jeweler on the Nieves. At least that is the conclusion that some have reached. A lot of unfinished jewelry and materials come from that site.

It seems they are producing a lot of 9 carat gold jewelry these days. And the trend is white gold. I prefer yellow - especially that nice buttery looking yellow of 22 k. But the 9 carat gold presents a little difficulty for those who use acid test kits to test or verify the carat value of found gold. Yes, most of this new jewelry will be marked, but if you want to test it, most gold kits come with test acid for 10kt, 14 and 18 kt, but not 9 kt. gold. I don't know why there is so much 9 kt gold jewelry being produced unless it is just the ridiculously high price of gold these days.

I was out of silver test acid and mentioned that one day. One person, I think it was Bill P., wrote in and told me that if you use 18 kt gold test acid on silver, the rubbing will turn blue. That seems to work. Thanks for the tip Bill.

It is good to have test pins which are tipped with known purities of gold, silver and possibly other metals like platinum. Test pins tipped with various purities and types of metals can be purchased from retailers that sell jewelry manufacturing equipment.

Make a rubbing of the known metal (say 14 kt if that is what you suspect the unknown metal might be) on the touchstone and then use the acid. Then after watching the results for the known metal, do the same for the metal to be tested. Compare the results. This procedure will help you further narrow down the purity of the gold or other metal.

For example, if you happen to have a gold ring that you know is 9 kt gold, you might start with a test on 14 kt first. Apply the 14 kt rubbing to the touchstone and apply the 14 kt test acid and observe the results. Then make a rubbing of the unknown gold and test it with the 14 kt acid. You will see that the 9 kt gold dissolves much faster than the 14 kt. So then you can do a test using 10 kt gold and use the 10 kt acid on that sample and then compare the results to the test on the 9 kt gold.

By using various samples of known purity and comparing the results to the unknown sample, you can pretty well arrive at the approximate purity of unknown samples.

If you want to test an object that is 16 kt, but you don't know that yet, you might test it and then compare the results with the results of tests done on 18 kt and 14 kt gold. You'll find that the 16 kt sample will react in a way that shows that it is between 14 and 18 kt.

I know that is not a great description of the process, but hope you get the idea.

Talking about platinum - platinum gives off the smoothest signal on many metal detectors. If you are practiced, you can often identify platinum targets from the signal. The signal will generally be not very loud, but very steady and smooth.

That is the kind of thing that you can learn to do with practice.

I often recommend playing around with your detector at home and using various types of test objects, especially those that you most want to find. You will develop an ear for the various types of signals and also learn how to adjust your detector's settings for maximum effectiveness.

Here is a nice web site by a beachcomber in Vera Cruz. It has lots of nice maps and illustrations and discussion about hunting shipwreck artifacts. The author shows spikes and various other finds. He describes the hunt in a very entertaining way.

Good read.

This web site provides a lot of useful tips for the detectorist. The things you do without a detector can really improve your success when using a detector. Studying maps, history and knowing about the area and having a strategy can really help improve your success rate.

Thanks to metal detectors, fragments of some of the earliest guns ever used one a British battlefield have been discovered.

I gave a link to this story before, but this link provides more on that story.

Forecast and Conditions.

With the cold fronts that have come through and the wind out of the north, there is actually some hope that the protective sand out in front of the beach is being moved. I don't know why, but it seems that north winds have a cumulative effect that gradually improves beach hunting conditions into the winter and spring. I have a theory on that, but it is only a theory.

As you know, the seas are only around five feet and have been that way for a while, so the hunting strategy hasn't changed. I'd still be scouting for dips and hunting the low tide areas.

At least the high tides are still nice and high. That helps some, especially with the non-metallic and artifact hunting.

Happy hunting,