Jewelry, Gems, & Minerals/Unknown ring



Ring 2
Ring 2  
I'm afraid I know nothing about gems and metals in jewlery. This ring could be very well made out of tin for all I know, but I would really like to know more about it.

It is made of four small greenish gems, which are surrounded by four clusters of small clear gems.
The marks on the inside of ring itself include the letters DIA, a set of scales with the number 375, 375 on its own, and an anchor. Excuse my lack of basic jewlery knowledge but I would love to know what all of this means.

I don't expect it to be anything special, but I'm curious about the materials it is made from. My apologies for the poor quality of the images and lack of details but I would love to hear any information you could give me

Many thanks, Karen

Jewelry markings are out of my field of expertise (I am a mineralogist), but I can give you at least some idea according to my limited background in jewelry and precious metals.
375 in a scale and on its own denotes the purity of the gold used in your ring. A 375 ring contains 37.5% of pure gold with the other 62.5% being more durable metals mixed in such as copper and zinc. This marking is commonly used in Europe. For the US this translates into 9 carat (9ct) gold.
The anchor is a symbol for the British assay office, in your case Birmingham (anchor) verifying the purity of the ring. It is actually illegal to sell jewelry over there in Britain without the official stamp of the assay office. This tidbit gives you at least some idea about the origin of the ring.
DIA is most likely what the Brits call the Sponsor's mark which are the initials of the dealer or manufacturer. The assay office in Birmingham keeps a data base of all these Sponsor's marks registered with them. Unfortunately the data base is not publicly available but you can contact the assay office in Birmingham and they will let you know.
There actually should be another stamp in your ring, a single letter, denoting the assay year and therewith dating your particular piece of jewelry.
Here is the website for the Birmingham Assay Office which explains many of the things I have discussed in this little expose':
As far as the stones in your ring are concerned it is hard to tell form the picture. The clear stones might be diamonds. The green stones could be a variety of things. Possibilities include emeralds, peridots, green tourmaline, chrysoberyls and many more. I might need a close up and possibility some physical testing to tell you for sure.
Sorry that I can't be more specific.

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Uwe Richard Kackstaetter, Ph.D. (Dr.K)


I can answer questions concerning minerals, mineralogy, gems, metals, and anything that has to do with geology. However, I am NOT a jeweler. Questions about values, settings, gem stone cuts and appraisals are best directed to other experts on this site. I can however aide in the identification of unknown mineral materials. As a public service and part as training for new geoscientists, our university department provides FREE mineral identification for individuals. Please contact me for details or go to for details..


I am a professor of applied geology and mineralogy with many hours of field experience. Furthermore, I enjoy recreational gold prospecting and mineral collecting. As a professor I am engaged in research concerning minerals and their occurrence.

Member of the GPAA (Gold Prospectors Association of America) as well as the Association of Environmental Geochemists. Member of the GSA (Geologic Society of America) Member of the AIPG (American Institute of Professional Geologists)

Here is a small sampling: Mineral-rock handbook: Rapid-easy mineral-rock determination : written for anyone interested in minerals and rocks - Proctor, Peterson, and Kackstaetter;Macmillan Pub. Co. (New York and Toronto and New York) Physical Geology Laboratory e-Manual [CD-ROM], Kackstaetter, Earth Science Education LLC Colorado Front Range Self-guided Geology Field Trips, Kackstaetter,

Ph.D. in Applied Geology and Mineralogy. I am actively teaching courses in mineralogy and a variety of field courses with mineral collecting opportunities. Background in precious metal exploration.

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