term jade is used for two different minerals, jadeite and nephrite. Only
jadeite has value as a gem material in and of itself.
jadeite, the intensity of the green
color, combined with a high degree
of translucency are the key factors
in judging value. Stones which are
too dark in color or not so translucent
are less highly valued. Ideally,
color should be completely even to
eye, without spotting or veins. In
lower qualities, fine root- or vein-like
structures that contrast with the
body color of the stone may be considered
attractive. However, dull veins or
roots are less desirable. Any form
of mottling, dark irregular specks,
or blotches that detract from the
appearance of the stone will reduce
basic elements of any color are hue position (top), saturation
and tone (bottom). Note that saturation and tone are interrelated.
As saturation increases, so does tone (lower left). However,
there reaches a point where increasing absorption of light
(increasing tone) results in a decrease in saturation (lower
right). Illustration © Richard
is another important factor in evaluating
quality. The best jadeite is semi-transparent;
opaque jadeite or material with cloudy
patches typically has the least value.
It is interesting to note that even
if the overall color is uneven or low
in saturation, jadeite can still be
quite valuable if it has good transparency.
jadeite, texture is intimately related
to transparency. Typically, the finer
the texture, the higher the transparency.
Further, the evenness of the transparency
depends on the consistency of the
terms of clarity, fine jadeite
should be free from noticeable or distracting
inclusion defects. This refers
to imperfections that impair the passage
of light. The
finest jadeite has no inclusions
or other clarity defects that are
to the naked eye. Typical imperfections
are mineral inclusions, which usually
are black, dark green, or brown,
but may be other colors. Black
visible to the eye are a particular
problem because the Chinese associate
them with bad luck. White spots
also are common, as are other intergrown
minerals. The most severe clarity
defects in jadeite are fractures
unhealed), which can have an enormous
impact on value because jadeite
symbolizes durability and perfection. That said,
virtually all jadeite has feathers
that are visible under magnification.
jadeites are usually cut as cabochons.
Material used for cabochons is
generally of higher quality than
for carvings, although there
With cabochons, the key factors
in evaluating cut are the contour
the dome, the symmetry and proportions of the cabochon, and its
thickness. Cabochon domes should
be smoothly curved, not too
high or too flat,
and should have no irregular
flat spots. Proportions should
not too narrow or wide, with a pleasing length-to-width ratio.
to certain rare colors of diamond (such
as blue, pink and red), jadeite is
the worlds most expensive gem,
with prices above even ruby and sapphire.
The record price for a single piece
of jadeite jewelry was set at the November
1997 Christies Hong Kong sale:
Lot 1843, the Doubly Fortunate necklace
of 27 approximately 15 mm jadeite beads,
sold for US$9.3 million (see figure
25). Indeed, out of the top ten most
expensive jewels sold worldwide by
Christies in 1999, five out of
ten were jadeite, including three of
the top four. These auctions clearly
show that jadeite is among the most
valuable of all gemstones. The most
valuable jadeites are those of high
translucency and rich Cr-green color.
has little value as a gem in and of
itself, but carvings can be quite valuable.
jadeite sometimes occurs in pieces
of several tons or more, top cut jadeite
of even five carats is large and quite
when fine jadeite cabochons are mounted
in jewelry, they are backed by metal.
The metal acts as a foilback of sorts,
increasing light return from the stone.
Often, a silver-colored plating is
added to the inside of this backing
to further increase reflection. The
metal generally contains a small hole
in the center, so one can shine a penlight
through the stone to examine the interior,
or probe the back with a toothpick
to determine the contours of the cabochon
base. When this hole is not present,
one needs to take extra care, as the
metal may be hiding some defect or
The name jade is
derived from piedra de hijada, the
Spanish name for jade. The Spanish
adventurers in the time of Cortes brought
back the jade pieces which they found
among the Indians. The Spanish translation
means “stone of the flank or
loins,” or “colic stone.” It
is believed that the flat polished
pebbles with rounded edges resembled
the kidneys, and would, therefore,
be efficacious in disorders of that
organ. Hansford states that the Spaniards
knew the stone as piedra de los
rinones (‘kidney stone’),
a name which was translated into Latin
as lapis nephriticus and this
gives the word nephrite.
1863, French mineralogist Alexis Damour
analyzed bright green jades from Burma.
When he found these samples to be different
from what was called Chinese jade (usually
amphibole jade, or nephrite), he named
the mineral jadeite.
|Top left: This jadeite
boulder shows the relatively thin skin and potentially good color
that is usually associated with river jade. Although
from the outside this appears to be a normal jadeite boulder, oxidants
that entered through cracks on the surface have produced a large
area of discoloration. Bottom left: Note the thick yellow mist around
the jadeite in this boulder of mountain jade. Right:
A key advantage to jadeite taken from in situ deposits is that
the quality of the material is readily apparent. Photos © Richard
most important source of gem quality
jadeite is Upper Burma, near the small
town of Hpakan. Today, virtually all
top-quality jadeite is produced from
these mines. Other jadeite localities
include Guatemala, Russia, Kazakhstan,
Japan and California, but all pale
in comparison with Burma. No gem-quality
jadeite is found in China. Ancient
Chinese jade is nephrite, and was mined
in far western China near Khotan. Nephrite
is also produced in Taiwan, British
Colombia, Alaska, Wyoming, Australia,
Russia and New Zealand.
the vast majority of jadeite is dipped
in wax as a final finishing step. This
is considered a normal trade practice.
All other enhancements are considered
abnormal and adversely affect value.
Some jadeite is dyed green or other
colors and these dyed colors may fade
with time. Other jade is bleached and
then impregnated with a polymer (b-jade).
As with all precious stones, it is
a good practice to have any major purchases
tested by a reputable gem lab, such
as the GIA or AGTA,
to determine if a gem is enhanced.
jadeite was first produced by General
Electric, and the process now produces
material of quite fine quality. However,
such material is rarely seen and is
mostly experimental. Imitation jades
abound. These include green glasses
and natural gems such as hydrogrossular,
serpentine and many others.
the various gems, no single stone has
a closer relationship with a culture
than jade with the Chinese. It is considered
the “Stone of Heaven” and
is thought to provide a bridge between
this world and the next. Jade also
played an important part in Mayan and
Maori cultures. In each of the above
cultures, jade was considered “beyond
above stone is a fine example of Burmese jadeite. Photo: Wimon
of Jadeite Jade
Various shades of green, lavender, white, colorless, brown, orange
(+ 0.06, –0.09)
(±0.008); spot RI 1.66; birefingence usually not measurable
Biaxial; aggregate polariscope reaction
line at 437 nm; Cr-green may have lines at 630, 655, 690 nm
occurs as massive polycrystalline aggregates
special care needed for untreated jadeite; treated jadeite may
be damaged by ultrasonic and/or steam cleaning; solvents, acids
jadeite is wax dipped; some jadeite is dyed and/or bleached and
but quite rare in the market
Russia with Jade – Pala Internationals
Richard Hughes, together with Nickolai Kuznetsov, make an epic journey
to Russias jadeite mines in the Polar Urals and Khakassia. Fully
- Burmese Jade: The
Inscrutable Gem – Part 1: Burmas Jade Mines
A groundbreaking article on the second-most valuable gem in the world – Burmese
jade. By Richard Hughes, Olivier Galibert, George Bosshart, Fred Ward,
Thet Oo, Mark Smith, Tay Thye Sun and George Harlow. Fully illustrated.
- Hughes R.W. (1999) Burmas
jade mines: An annotated occidental history. Journal of the
Geo-Literary Society, Vol. 14, No. 1, pp. 15–35.
- Hughes, R.W., Galibert, O. et al. (1996–97) Tracing
the green line: A journey to Myanmars jade mines. Jewelers Circular-Keystone, Vol.
167, No. 11, Nov, pp. 60–65; Vol. 168, No. 1, Jan, pp.
- Hughes, R.W. and Ward, F. (1997) Heaven
and hell: The quest for jade in Upper Burma. Asia Diamonds, Vol.
1, No. 2, Sept-Oct, pp. 42–53.
The Collector Gem Buying Guides
In addition to the above, please visit the Learning
Vault at Palagems.com for many additional articles on gems, minerals and mining.