
Pearls are the only gems found within living creatures, both salt and freshwater mollusks. Thus, some traditional stones remain popular. Some traditional gems are also less expensive (like turquoise) or more readily available (like cultivated pearls) than their modern counterparts. In the United States today, people draw freely from both lists and pick the stones that appeal to them. For example, spinel, citrine, and tanzanite are recent moder additions. To this day, jewelers continue to add options to the modern birthstone chart. (Imagine trying to create a ring with a pearl, a turquoise cabochon, and a diamond and emerald, both faceted). Presumably, this made it easier for jewelers to create “mother’s rings,” which feature the birthstones of a woman’s children, in a manner more suited to modern tastes.

In 1912, the National Association of Jewelers released a list of so-called “modern birthstones.” The modern list differed somewhat from the traditional, most notably by including only transparent gems. The list of traditional or ancient birthstones most well-known in the United States actually originated in Poland between the 16th and 18th centuries.
