A mother's ring is a type of memorial jewelry. It has a birthstone for each of the children of a woman, either living or dead. They can represent a mother or grandmother's family, can include birthstones for other family members, and can be given upon the birth of a new child or grandchild.
It started as two wedding bands joined together by the birthstones of the sons of a couple, which sold very well during the Mother's Day season as a present to your own mother or to your wife.
The name is trademarked since 1959 by jewelry company John C. Nordt Co.
Standard birthstone rings feature the birthstone of the ring's wearer, but mother's rings include the birthstones of all of her children. In some cases the birthstones of the parents are also set in the ring. Some are also personalized with the names of family members, or the family name.
Similar rings, often featuring the birthstones of both her children and grandchildren, are sometimes given to grandmothers as well. These rings are popular Mother's Day gifts, and are often given to a mother or grandmother upon the birth of a new child or grandchild, both as a new ring or to replace an old one.
^National Arbitration Forum, John C. Nordt Co., Inc. v Jewelry Exchange  GENDND 741 (11 April 2001) Claim Number: FA0103000096789, "MOTHER’S RING is a registered trademark of Complainant. The mark was registered for "rings" with the United States Patent and Trademark Office on July 7, 1959 as Registration No. 681,459. Complainant also owns a United States Registration No. 868,383 for THE MOTHER’S RING, also for "rings," which issued on April 22, 1969. Complainant’s trademarks, MOTHER’S RING and THE MOTHER’S RING, have become incontestable. Goods have been sold under one or both of those trademarks throughout the United States for over forty years and the trademarks are widely known in the jewelry business and among the jewelry-buying public. (...)"