Jade Primer

Jade stone, explained plainly

What jade is, what it is worth, and how to tell the real stone from the imitations.

What jade stone is

Jade is not one stone. Gemologists use the word for two different materials, jadeite and nephrite, as the Gemological Institute of America (GIA) describes them. Both are rocks made of tiny interlocking crystals, which is why jade is so hard to break even though it is not especially hard to scratch. For most of history they were treated as a single stone. Only in 1863 did the French mineralogist Alexis Damour show that the jade coming out of Burma was a different mineral from the jade long carved in China, and the Burmese material was named jadeite.

The two differ in ways that matter to a buyer. Jadeite is slightly harder and noticeably denser, comes in brighter colors, and supplies nearly all of the most expensive jade sold today. Nephrite is the stone of ancient Chinese carving, usually more muted in color, with a soft, waxy polish. Each has its own varieties and trade names, and each is judged by its own standards.

Jade comes in far more than green. Jadeite occurs in green, lavender, red, orange, yellow, white, black and gray, and nephrite in green, white, yellow, brown, black and gray. Green is the most valued color in both, but the shade and how evenly it sits in the stone count for more than the name of the color. For jadeite, GIA ranks color first, then transparency, then texture.

Two questions decide what any piece is worth. The first is whether it is jade at all: serpentine, quartz, dyed calcite, glass and plastic are all sold under jade names. The second is whether it has been treated. A stone can be genuine jadeite and still have been bleached and filled with resin or dyed, and that treatment cuts its value to a fraction. Home checks can narrow both questions down. A report from a gemological laboratory is what settles them.

Common questions about jade stone

What is jade stone made of?

Jade is a name for two different stones. Jadeite is a sodium aluminium silicate of the pyroxene group, and nephrite is a calcium magnesium iron silicate of the amphibole group. They are unrelated minerals that look and behave alike.

Is nephrite real jade?

Yes. Gemologists use jade as a general term for both jadeite and nephrite. Nephrite is the older of the two in Chinese history, and the finest white nephrite is prized as highly as fine jadeite.

How can I tell if my jade stone is real?

Home checks such as heft, a loupe, a strong light and a UV lamp can rule out plastic, glass and some treated stones, but none of them proves a piece is untreated. For anything of value, a report from a gemological laboratory is the only firm answer.

What color of jade is the most valuable?

Green. For both jadeite and nephrite, green is the most valued color, and for jadeite the Gemological Institute of America ranks color first among the value factors, followed by transparency and texture.

Why is some jade so cheap?

Much of the inexpensive jade on sale has been bleached and filled with resin or dyed, or is a different stone sold under a jade trade name. Treated jadeite is worth a small fraction of the same piece left natural.