Gemstones Information about gemstones January - Garnet February - Amethyst March - Aquamarine, Bloodstone April - Diamond May - Emerald June - Alexandrite, Pearl, Moonstone July - Ruby August - Peridot, Sardonyx September - Sapphire October - Opal, Tourmaline November - Topaz, Citrine December- Blue Zircon, Tanzanite, Blue Topaz, Turquoise