Lemon quartz is sometimes referred to as 'Oro Verde' and it is often confused with citrine quartz, due to its very similar appearance. In fact, the line that distinguishes citrine quartz from lemon quartz is somewhat debatable. In general, for quartz to be traded as 'citrine', it must be naturally colored or enhanced by heat-treatment only. Lemon quartz is typically lemon-yellow and is often accompanied by a greenish tone. Citrine on the other hand, tends to have heavier orange tones.
Lemon quartz obtains its brilliant sparkling color through an artificial gamma-ray irradiation process followed by a mild heat treatment. Not all quartz can be made into sparkling lemon quartz. Most aluminum-rich quartz will turn near-black to black when irradiated; though some yellowish-brown aluminum-rich quartz can be used to produce lemon quartz if it is first heated and then irradiated. Heat causes the material to lose its color and when it is exposed to irradiation, the yellow color returns. Also, lithium-rich quartz that is exposed to very mild heat (140-280 °C) tends to turn yellowish-green even without irradiation. These could be traded as both citrine or lemon quartz, since they are not irradiated.
According to the Nuclear Regulatory Commission (NRC), there is no residual radiation left over after the quartz has been exposed to gamma-ray irradiation, which means these gemstones are perfectly safe to handle and wear. The company behind the treatment and making of lemon quartz is known as Empresa Brasileira de Radiacoes Ltda., and is located in Brazil. This company is also known for enhancing the colors of a number of other gemstones, including the 'green prasiolite' seen on the market today. It is almost impossible to identify artificially irradiated quartz, so it is safe to assume that most lemon-yellow colored quartz has been irradiated, although only proper lab testing can confirm this for sure.
The color yellow is often associated with clarity, happiness and communication, and lemon quartz is thought to bring balance and positive energy to its wearer. It is a very popular and affordable gemstone. Very clean and large stones can be found, even in sizes over 150 carats. A chatoyant variety that exhibits asterism is traded as 'star lemon quartz'. Like all quartz gemstones, lemon quartz is considered to be very durable and is therefore suitable for all types of jewelry.
- First Published: July-28-2014
- Last Updated: August-16-2017
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