Citrine is a rare variety of quartz. Natural citrine is often a pale yellow
or orange. Much of the citrine found in jewelry today has been heat treated
to create rich colors such as yellow-brown, reddish brown, golden orange,
and orange brown. In fact, citrine is often created by heating amethyst
to change the gems color to a golden yellow with reddish tint.
Sometimes amethyst deposits that have been sujected to naturally high temperatures create
a bi-colored quartz called amertine which combines the colors of amethyst and citrine.
The origin of the tradition of birthstones is sometimes attributed to the Breastplate of Aaron, the high priest of Hebrews.
The breastplate of the high priest was a ceremonial garment set with 12 gemstones, each stone representing one of the
twelve tribes of Israel. The twelve gems corresponded to the twelve months of the year, and the twelve signs of the zodiac.
Citrine is the modern birthstone for November, and the planetary stone
Citrine has a Mohs scale hardness rating of 7.