Back to Materials Citrine Citrine is a type of quartz (silicon dioxide). The yellow is from iron hydrate impurities. Natural citrines range from very pale yellow through to strong yellow to an almost brown colour. Citrine is quite rare in nature and the main source for natural citrine is Brazil. Because of its rarity the price of natural citrine is much higher than most other quartz varities such as amethyst and rose quartz. Unfortunately this has led to some people heat treating amethyst, which turns the purple hue to a yellow/red hue, and then sold as citrine. Many people don`t realise the difference between heat treated amethyst and citrine, but if you see orange to red citrine, buyer beware! Citrine beads and stones can have fractures, pits, impurites, and those stones that are perfectly formed and cut by a professional can be many hundreds of pounds in value. Even low grade citrine is usually 4 or 5 times more expensive than an amethyst bead of similar size and quality. Citrine has a specific gravity of approximately 2.65 (2.65 times the weight of water by volume) which is the average value for quartz minerals, and its hardness value is 7.0 on the mohs scale.