Zircon, or zirconium silicate, ranges in color from red, brown, yellow, and green to gray and colorless varieties. Colorless zircon is called jargoon or Matara diamonds (19th century), and flame colored zircon may be referred to as hyacinth. It is a radioactive gem, and many specimens contain thorium, uranium, and hafnium, which slowly destroy the crystal structure through a bombardment of alpha particles. A reddish-brown variety of zircon, called cyrtolite, is indisputably radioactive. Most mined zircon is never converted into gemstones. It is used instead as an ore to harvest the thorium, uranium, and hafnium.
When looking at specimens for sale, "high" zircon refers to stones, which are presently unaffected while "low" zircon may already display signs of decay. Low zircon will have a dark, pitchy appearance and a nebulous internal structure. Heat treatment will sometimes restore low zircon, but it will eventually revert to its decayed state. The exposure to radiation of a heat-treated zircon will almost certainly cause it to revert to its natural brown stone.
Zircon is sometimes referred to as a "stone of virtue," endowed with the ability to reestablish or realign your ethics or morals with the universal truths if you feel they are slipping. The qualities of innocence, purity, and constancy are emphasized. It also promoted unions, whether of the mind, body, spirit or emotion. Your stamina and perseverance may also be increased through the use of zircon. Yellow zircon, called ligure, was used during the Middle Ages to attract love and heighten sexuality, while orange zircon, or hyacinth, was considered a protective stone. It was used to procure the safe passage of travelers and to assure the traveler of a friendly welcome no matter where they went. Red and brown zircon healed injuries and soothed pain, and brown zircon, the most prevalent hue, is also excellent for grounding.