I Think Therefore I ... Amethyst!
As you know, February's birthstone is that most sumptuous and mysterious of gems, Amethyst. One of the most popular gemstones it has been considered valuable since ancient times. It is a variety of Quartz that occurs in hues ranging from a light pinkish violet to a velvety purple, the transparent deep purple colours being the most highly regarded.
Amethyst was once as highly regarded as the precious gemstones such as Ruby and Emerald but discoveries of huge amethyst deposits since the 1800's have made Amethyst more easily obtainable and therefore fairly inexpensive. The highest grade amethyst, called "Deep Russian" is, however, exceptionally rare and its value is dependent on the demand of collectors.
According to the Gemalogical Association of America, "The essence of the color purple, Amethyst is beautiful enough for crown jewels yet affordable enough for everyday wear."