Later, birthstones became associated with calendar months rather than the zodiac. People began selecting birthstones in colors other than the original colors. The Roman, Arabic, Jewish, Polish, Russian and Italian lists were all different. In 1912, the American National Association of Jewelers, which later became Jewelers of America , adopted the list as we now know it. Refer to our birthstones page for more information.
Gemstones are minerals.
The exceptions would be pearl and coral, which are of animal origin, and jet and amber, which are vegetable. These minerals have been crystallized as a result of high temperatures and pressures exerted by the natural forces of the earth's crust. Gems were once divided into these categories, but today this is no longer true. Discoveries have added new varieties to the traditional selection of ruby, sapphire and emerald. Some of the more unusual gemstones command a higher price than a more well known gemstone because of their beauty and rarity.