Citrine is the yellow/golden variety of Quartz and comes in a full range of tones from basically very light yellow to a rich golden reddy brown. Sources are worldwide but major producers are Brazil, Uruguay and Zambia. Since naturally occurring Citrine is quite rare, a lot of the material on the market is the result of the heat treatment of Amethyst. This treatment causes some Amethyst to change colour from undesirable pale violet to an attractive yellow. The treatment is very prevalent and is considered permanent and standard in the industry. We sell Citrine from several sources but mostly Brazil, which in all probability has been heated, however the Citrine we sell from Zambia is guaranteed natural and untreated since we buy directly from the miner.