Garnet, January’s birthstone, is a multifaceted gemstone that comes in every color except blue. Though most commonly found in deep reds, the garnet also takes form in rich oranges, greens, and softer pinks and purples. Soldiers in the 18th ­century often carried garnets to heal wounds because the red gem was believed to influence the blood. For good health and sweet dreams, mothers in medieval Europe would hang the translucent green hydrogrossular garnet above their babies’ cradles. The name derives from the Roman word for seed, granatus, as the gems were often thought to resemble pomegranate seeds.