Various birthstone lists have been used in different cultures for thousands of years.
The traditional birthstone list is based on birthstone traditions from the fifteenth to the twentieth century. Since then, many of the traditional stones on the list were changed to correspond with stones that were more commercially available. In 1912, the American National Association of Jewelers adopted a list which included alexandrite and that was accepted as the standard in the United States and many other countries. In 1952 the American National Retail Jewelers Association, the National Jewelers Association and the American Gem Society approved a variation of the list. In this list, alexandrite is offered as an alternative to pearl and therefore associated with the month of June. It is also suggested as the gemstone for a 55th wedding anniversary (sometimes also the 35th or 45th in place of emerald).
Certain months offer various options for the modern birthstone. For example, for those who want to purchase the birthstone for June, alexandrite, pearl or moonstone may be chosen. Pearls are a classic choice, while natural alexandrite is expensive and rare. In response to the costs associated with alexandrite, some retailers have selected their own stone to represent the month of June, including green tourmaline to represent the green color of alexandrite, or pink tourmaline to represent the red, or color change garnet because of the change.