The January birth stone for folks born in January is garnet. Garnet is a deep red color, much like a pomegranate seed. The name "garnet" and the "granate" in "pomegranate" both come from the Latin word granatus which means "grain".
People born in January will become more firm and steadfast. Those are two qualities that contribue to the garnet gemstone's power for making you more successful in business. Garnet is also believed to cure depression. I think this is also related to those two qualities, since being firm and steadfast means you are likely taking action and moving your life forward. It is in the state of constant improvement and progress that makes depression very unlikely.
It is a stone symbolizing purity and truth, and love and compassion. Combined with the qualities of firmness and steadfastness, these lead to a very well-rounded personality and spiritual state that allows you to be a successful leader.
Those born in January can experience enhanced power from the garnet gemstone, and wearing or having some nearby at all times is suggested.