August is one of three months that has three birthstones — sardonyx, peridot, and spinel. Sardonyx combines alternating layers of sard and onyx–two kinds of the mineral chalcedony–to create red, zebra- striped stones with white bands. Colors range from yellowish red to reddish brown, depending on how much iron oxide is present. Registering a 6.5, on the Mohs scale, sardonyx is associated with happiness, courage, and clear communication. Some believe that the placing sardonyx, at each corner of a house, will protect against evil. Peridot’s brilliant, lime green color comes from the composition of the mineral olivine. Associated with fortune and prosperity, peridots come in shades varying from yellow-green, to olive, to brownish green, depending on how much iron is present. Peridots also measure 6.5 – 7 on the Mohs scale. While they are thought to possess healing properties, and protect against evil and nightmares, they are also believed to ensure peace and happiness. While spinels resemble rubies and sapphires, it is spinels’ features–its single refraction and its octahedral crystal structure–that sets it apart from other gemstones. The most desirable spinels come in vivid red, cobalt blue, bright pink and bright orange, while less valuable spinels come in black, violet blue, greenish blue, grey, pale pink, mauve, yellow, and brown. Additionally, many English monarchs, including Henry VIII, truly prized spinels.