CITIUNE

Quartz, a silica mineral, comes in the translucent, coarse-grained variation called citrine (q.v.). Citrine is a semiprecious gem appreciated for its similarity to the more expensive topaz and its yellow to brownish colour. Citrine’s colour is caused by hydrous iron oxide contained in colloidal suspension. In contrast to amethyst or smokey quartz, both of which are frequently heated to change their natural colours into those of citrine, natural citrine is extremely rare. To drive up the price of citrine, it is frequently sold under several names that make topaz look similar. It can be recognised from topaz by its lower hardness and from amethyst that has lost its colour by not having a reddish hue. Amethyst is most commonly found in the following places: Brazil, Uruguay, the Urals, Scotland, and North Carolina. It has quartz-like physical characteristics