The term 'birthstone may' is associated with nine different gemstones. EMERALD (7 letters) is a green gemstone that is known for its beauty and is the birthstone for May. AMETHYST (8 letters) is a purple gemstone that is often used in jewelry and is also the birthstone for May. OPAL (4 letters) is a gemstone that has a unique play of color and is the birthstone for May. TOPAZ (5 letters) is a yellow-orange gemstone that is often used in jewelry and is the birthstone for May. GARNET (6 letters) is a deep red gemstone that is known for its beauty and is the birthstone for May. PEARL (5 letters) is a white gemstone that is often used in jewelry and is the birthstone for May. SAPPHIRE (8 letters) is a blue gemstone that is known for its beauty and is the birthstone for May. GEM (3 letters) is a general term for any precious or semi-precious stone and is the birthstone for May. PERIDOT (7 letters) is an olive-green gemstone that is often used in jewelry and is the birthstone for May. RUBY (4 letters) is a red gemstone that is known for its beauty and is the birthstone for May.