Jadeite is a mineral with a hardness of 7 out of 10 on the Mohs scale of mineral hardness [?]. These Monoclinicly structured gems are made of sodium aluminum silicate, their full chemical compound being Na(Al,Fe) Si2O6.
Jadeite is a silicate of sodium and aluminum, and is a member of the Clinopyroxene group of minerals. It is so called because it is the source of one of the ornamental materials commonly known as Jade.
It has a monoclinic crystal system, and occurs as granular aggregates of small crystals, but has occasionally been found in crystals of a few centimeters. The color varies a great deal because of the minimal differences in composition.
It is off-white or grayish-white, but it may be brown, yellowish brown, orange-yellow, reddish orange, lilac, blue-gray, or various shades of gray and green.
It is hard, insoluble, with extraordinary tenacity for a mineral, especially one in which the tiny individual crystals sometimes display obvious cleavage traces.
Jadeite is formed by regional metamorphism and occurs in lenticular masses or veins. It is also found as alluvial pebbles and even boulders.
Jadeite comes mainly from Northern Burma, where it is recovered from rock rather than alluvium. Very small quantities of jadeite are also found in Japan, Tibet, California (USA), and Guatemala, where many items were made from it in antiquity. It is also found as small crystals in the Swiss Alps.
Numerous green opaque stones have been falsely offered under the name "jade."
There are distinctions between Jadeite, Jadeite jade, and Jade. But precious jade is always Jadeite.
The specific gravity [?] for Jadeite is 3.33, it's refractive index [?] is 1.66-1.68, and it's double refraction [?] is 0.012.
History
Jadeite is word possibly derived from the Spanish "ijada" or "flank," due to its alleged therapeutic action on diseases of the kidneys. People believed that if a piece of jadeite was worn close to the diseased organ, it had the power to cure it.
For more than 2,000 years, jade was part of the religious cult in China and mystic figures and other symbols were carved from it. In pre-Columbian Central America, jade was more highly valued than gold. With the Spanish conquest, the high art of jade carving in America came to a sudden end. But in China, this art was never interrupted. In former times only nephrite was worked in China, but for the last 150 years jadeite imported from Burma has also been used.
In 1863 a Frenchman proved that two minerals were considered to be the same tough stone, a gemstone which had been known for 7,000 years. He named one jadeite, and the other nephrite. Differentiation between jadeite and nephrite is very difficult, and this may be the reason why the word jade is used as a description for both.
Industrial Usages
The market value of jadeite has risen, often rivaling that of fine ruby and sapphire. It has become increasingly important to understand the color origin of jadeite, and reliable determining treatments have become increasingly important.
Jadeite is a term used in the gem industry to refer to two different minerals: jadeite and actinolite (variety nephrite).