The birthstones by month, beginning with January, are: garnet, amethyst, aquamarine, diamond, emerald, pearl, ruby, peridot, sapphire, tourmaline, topaz and tanzanite. June, October, November and December have alternatives, which are: Alexandrite for June, opal for October, citrine for November, zircon and turquoise for December.
Birthstones are gems representing a certain month in the year, each also carrying a certain meaning that has evolved over time. Sometimes people use their birthstones as the preferred gemstone for jewelry that they wear. Each month could have more than one birthstone attached to it, with different countries having different ideas of what gems are birthstones.
Modern birthstone lists differ quite widely from the original lists. Birthstones once held religious meaning in the Western hemisphere, and the Hindu text Mani Mala lists a similar set of gems with key differences associated with Eastern gemstones. One Hindu birthstone is a golden siva-linga, or lingam, which is associated with Hindu culture and religion.
The original Western association with the Foundation Stones of Christianity has since been lost, with some of the original stones changed. Some scholars who comment on the subject believe that the modern lists are a product of salesmanship, meant to sell gemstones as opposed to ascribe any meaning to them.