8/6/25 Report - Genstone Jewelry. Methods of Identifying Stones and Possible Implications. Mohs Scale and Black Lights.

Written by the TreasureGuide for the exclusive use of the Treasure Beaches Report.

Corroded Rings After Rock Tumbling.

Yesterday I posted a picture of a ring found by John H.  Mark G. sent the following message and photos and mentioned that ring.

Last December during the first winter fronts to come through I was hunting the wet cuts from Santa Lucia Beach where John H. found his silver ring north to the hotels and I found 3 silver rings over 2 hunts. Very tarnished/corroded been there a long time and yes they may never look new again but John H. may have a shot at shining his up. I use a jewelers polishing/burnishing media in my rock tumbler (2 hours at a time) for all my jewelry and it will make your jewelry look new again. I use a concentrated tarnish remover liquid made for tumbling jewelry. I put these 3 rings in every time I run something and each time they get a little smoother and a little shinier. If the stone is real it should not hurt it.

Mark G.  

A Couple of Mark's Corroded Ring Finds Before Cleaning.

Not too long ago, maybe a month or two, I did a series of posts on cleaning methods, which included tumbling and electrolysis and maybe some others, but there is an important issue I didn't mention in that series.  Some rings have gemstones, which brings up another issue to consider when you select a cleaning method.  A gemstone can be the most valuable or interesting part of a ring, so you might want to consider more than the type and condition of the metal.  

I've made my share of mistakes over the years, but one thing I've learned is that it is a good idea to know what you are dealing with before taking action.  I'd rather not clean something than clean it and cause damage that I ended up regretting.  I've done that.  I've overcleaned a coin using electrolysis and I've damaged some very nice items by tumbling them.

John's ring presents an interesting issue and one I don't think I have addressed for a long time.  It depends upon the individual case, exactly what you have and how you regard the item, but if you care about the stone, you might want to take that into consideration.  In the case of John's ring, it holds a pietersite stone, which is not one of the more common gemstones.  Pietersite, like any gemstone, has its own qualities and characteristics.  Again, you will want to find out what you have.  That may require researching gemstones and settings.

I've posted on the topic before but unfortunately can't find the post I want right now.  That is one problem with Google blogger.  It is sometimes difficult to find an old post when you look for it, but I once posted a nice list of gemstones along with their properties.  I also did some posts on how to identify or evaluate diamonds and a few other gemstones.  Here is one of those posts on evaluating diamonds.

The Treasure Beaches Report Direct From Florida's Treasure Coast.: 9/9/13 Report - Found Diamonds and A Little About How to Evaluate Them

As you probably know, there are gemstone testers that can identify diamonds, rubies, sapphires, emeralds and more.  There are also other methods of identifying your gemstones.  One easy thing to do is take your find to a trusted jeweler for an evaluation.  Most jewelers will charge a decent fee for a formal appraisal, but a quick verbal opinion can often be obtained free.

One characteristic that distinguish gemstones is hardness.  Here is what I previously posted in 2020 on the mohs hardness scale.  

A scratch test can be especially useful when testing gems.  Below is a brief table giving the relative hardness for some items.

                                                                                                                           Cutting
Scratch           Mineral Used                                                                              Hardness
Hardness        For Compar-
(Mohs)            ison.
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1                      Talc                  Can be scratched with fingernail                              0.03
2                      Gypsum            Can be scratched with fingernail                             1.25
3                      Calcite              Can be scratched with copper coin                          45
4.                     Flourite             Easily scratched with knife                                      5.0
5.                     Apatite              Can be scratches with knife                                     6.5
6.                     Orthoclass         Can be scratched with steel file                              37.0
7.                     Quartz               Scratches window glass                                          120.0
8.                     Topaz                                                                                                 175.0
9.                     Corundum                                                                                         1000.0
10.                   Diamond                                                                                       140,000.0

Table from Gemstones of the World, by Walter Schumann, 1984.

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That is a big range.  But as you can see, not only will a diamond scratch glass, but so will quartz.

You can find much more complete tables giving the hardness of various gems.  In fact the same book provides the characteristics, including hardness, of most gems and minerals.

Here is that link to that old post.

The Treasure Beaches Report Direct From Florida's Treasure Coast.: 3/18/20 Report - Interlocking Rings. Hardness and Other Materials Tests and Observations. Mayan Find.

You can find a list of 185 gemstones by using the following link.

Gemstone Hardness | Mohs Scale with Images and Charts

You think of diamonds as being very hard, and they are hard, but they can be chipped.  You might learn that the hard way.  You can accidently knock your ring against a hard surface and chip an expensive diamond, causing a big decrease in value.

Another characteristic of some gemstones is fluorescence.  Some gemstones will fluoresce in black light.  In addition to helping you identify some stones, that characteristic can also help you find them.  I've used a black light to find rubies in dirt.  It works very nicely.  I used a simple black light I still had from back in the seventies.

The corundum family including rubies, garnet and sapphires, which will fluoresce under black light.  I understand there are some cases when they might not, depending upon such things as their origin and treatment, but I've found a black light to be helpful.

Here is a link that provides more information on that.

Black light and gemstones

I've done a few posts about using a black light.  A black light can reveal some interesting surprises.

One of my favorite finds and one of my all-time most read posts includes using a black light to discover something very interesting about a piece of red sea glass. Here is a link to show what it revealed.

The Treasure Beaches Report Direct From Florida's Treasure Coast.: 9/17/15 Report - How One Artifact Continues To Reveal More Of Its Story. Tropical Depression Nine.

Here is another all-time most viewed post that involves the use of a black light to illuminate fossil shells and calcite crystals.

The Treasure Beaches Report Direct From Florida's Treasure Coast.: 5/28/15 Report - Unique Beach Treasures. Fossil Shells With Calcite Crystals

Black light will also cause depression glass and Vaseline glass to fluoresce.  I think I also provide a couple examples of that in those posts.

I've said before, a magnet is a very much underappreciated tool for detectorists.  Another very handy and under-appreciated tool is a black light.  I recommend considering how you might be able to use both of those.

Back to John's pierersite ring. Pietersite is not a very common stone and may not be listed in some charts or lists. Copilot (AI) says pietersite has a Mohs hardness of 6.5–7, which makes it softer than many tumbling media.  As a result, tumbling includes the risk of damaging the stone. John may or may not care much about that, but it is a consideration.  

I've made enough mistakes over the years, and I regret doing some things before I knew exactly what I was dealing with.  There are a few points I want to make today.  One is to do your research before taking action.  It is better to know exactly what you are dealing with so you can avoid some mistakes.  A delayed action can be the best decision.  

Another important point is that gemstones metal detecting finds can be more complex than the metal they are made of.  They can include other materials, including stones, which can be identified in variety of ways.  One important characteristic that will help you identify a stone is the hardness.  There are tests you can conduct yourself, but you can also get a jeweler's opinion.  Doing it yourself can be educational but there are also times when you want an expert opinion - especially when you might have a valuable stone.

Also, I've found using a black light to inspect finds both informative and interesting.  I've observed qualities and characteristics of finds with a black light that I would have never noticed without the black light.  You might consider purchasing one.   A black light can help you identify fossil shells, certain types of glass, gems and even highlight certain details on coins.

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Source: nhc.noaa.gov.

We are well into hurricane season now, and the Atlantic is getting active.

As you can see on the NHC map above, there are three areas of activity shown that could develop, but they all seem to be going away from us.

At this point, it doesn't look like any of them will affect the Treasure Coast very much.  

The surf has increased a foot or so though.  Still not enough to move a lot of sand though.

Good hunting,

Treasureguide@comcast.net