|January's birthstone is Garnet. Available in many spectral colors, most famous are Brown, Red-Brown and Violet / Purple stones that set nicely in jewelry categories. It's also the suggested stone for 2nd Anniversaries. This ancient stone is believed to be a sign of friendship, loyalty and devotion.
P.S. Green Garnet is called Tsavorite and rivals fine emerald qualitatively. It is also harder than emerald so it's safer without sacrificing beauty.