The large rectangular black stone may be Black onyx, Black Spinel, Black Tourmaline or Zircon all of which are quite common. Thanks very much. Hope thats useful. Weve seen rings from Pranda with natural gemstones including diamond. silver melted from coins which was typically 800 850 in purity. Some Patina remains. Looks very old. Your email address will not be published. Looking at your ring the 9K is likely the rose gold coloured outer bands. Marathon Co which has been in existence in various guises since the early 1900s uses various makers marks. 375 is a purity mark signifying the gold is 37.5 per cent pure. Is there a way to find our who made it . The 925 standard mark officially became the international convention in millesimal expression (i.e. If the 925 mark ring is also set with precious and/or semi-precious gemstones these will also add to the rings value. Large rectangular black stone, surrounded by chipped black stones. There is no location mark on the ring but it is likely to be made offshore with LA Gem having products manufactured in Thailand and China. What does jewelry stamped CN mean? Hope you could help me identify its meaning? PHOTO: What does CG925 mean on jewelry? Finally, the CN stamp likely refers to the country of manufacture i.e. Jewelers do such tests by applying acid to a very small piece of material taken from the jewelry. Rings marked 9K 925 PT should consist of a combination of three separate metals. What does the letters ATL BR CN stamped on a necklace mean? I hope youll have the financial success needed to sustain this effort. However they can also be a logo, brand name or some other unique representative symbol. A gem tester would confirm. The makers mark is the stamp representing the jeweller, manufacturer or brand which made the ring. That said, modern 925 jewelry markings are in many cases not catalogued or recorded as well as older vintage and antique makers and other jewelry marks. I received the ring from my grandmother and just trying to find out as much as I can about the ring. Weve looked at the photos you sent us and M stamp inside a diamond matches a later edition marking of Marathon Co of Attleboro, MA. The answer is that silver jewelry signed ss 925 F star or F inside a five pointed star was the work of Tara Jewels Limited or Tara Jewels Exports Pvt. What does that mean? In recent years affordable engagement rings have become increasingly sought after. PHOTO: 925 Jewelry stamped with a makers mark of an a letter R, crescent moon, 925 and copyright mark is the work of Relios Inc. of New Mexico. Youve asked what 925 CA means on a silver ring from Thailand. In 1973, the European Community (EC) agreed to recognize 925/1000 as the official sterling silver standard and 925 as the official standard mark.