Amethyst

Amethyst, the purple variety of quartz, has been used for personal adornment for thousands of years because of its luscious color. The name originates from ancient Greek: "a," meaning not, and "methysko," meaning intoxicate. Amethyst was thought to protect the wearer from drunkenness and until the 19th century, it was one of the cardinal (most valuable) gems along with emerald, sapphire, ruby and diamond. The finest examples were sought from mines in the Siberian Urals by Catherine the Great. By the early 1800s, a very large discovery of this gem was found in Brazil at which time it became more attainable.

Amethyst’s hue is derived from color centers and trace amounts of iron plus irradiation within the earth, and it can range from very pale lavender to a deep purple. The gem is also dichroic, meaning it has red and blue secondary hues. When this stone is exposed to very high heat it can be modified, for example changing the color to a golden hue (citrine) or, in some cases, ametrine (a mixture of amethyst and citrine) and prasiolite (pale green amethyst). Sources of amethyst can be found all over the world, with Rio Grande do Sul, Brazil being one of the primary sources along with Zambia, South Korea, and Russia. 

This lush purple gem was worn by ancient Egyptians, thought to be the tears of Dionysus in ancient Greek mythology, donned as an amulet to keep a cool head in Medieval times, and continues to be popular in 21st century fashion.