|
|
|
|
Jade
To many people jade and the color green are synonymous.
The word brings to mind the fabled past of ancient China,
the opulence of Oriental Emperors. In fact, the Chinese
worked a material they called “yu” as early as 1000
B.C. Today we know this material as jade.
|
|
The
name of the gem itself, however, is derived from the
Spanish name "piedra de Hijada," or "stone
of the loins." Cortes and his conquistadores brought
back to Spain many pieces of jade, which they found
to be in wide spread use among the Indians of Central
America. |
| |
|
The
term "jade" actually refers to two distinct and
different miner als: jadeite and nephrite. Jadeite is sodium
aluminum silicate; nephrite is a calcium magnesium silicate.
The name nephrite comes from the belief that polished jade
pebbles that sometimes resemble kidneys would help cure kidney
disorders. Thus, the name "kidney Latinized to "lapis
nephrite occurs," eventually was shortened to “nephrite.”
|
|
 |
 |
|
DIAMONDS,
GEMSTONES & CRYSTALS
FACTS & FIGURES |
| Jade
Nephrite
occurs in various colors, including greenish-gray
so-called "mutton-fat jade"), brown,
and dark green. The hardness on the Mohs scale,
but the physical structure of the material is
that of many interlocked crystals. Thus, nephrite
is extremely tough. Nephrite is also sometimes
called greenstone.
Jadeite consists of interlocked grains, but in
jadeite these are m, granular than fibrous, so
jadeite surfaces often have a "dimpled” The
hardness of jadeite is 7 on the Mohs scale, making
slightly harder than nephrite and providing one
distinguishing test.r eiteoccurs in an enormous
range ofcolors: white, pink, lilac, brown, orange,
blue, black, and many shades of green. A single
piece of elte will frequently display several
colors, with subtle changes of hue : shade in
different parts of the piece.
. 
The
most highly valued color is c h green resembling
that of the finest emerald. Translucent stones
of >uperb color, generally known as "Imperial
jade," may sell for ~ ral thousand dollars
per carat. The color range for jadeite is much
ner than that for nephrite. A black or dark-green
jadeite that contains ;e quantities of iron oxide
is called chloromelanite. |
|
|
 |
sephrite
has been used to make tools, weapons, and ornaments, )layed
a central role in the religious rites of many primitive
peoples, ding the Chinese, the Central American Aztecs,
and the Maoris of Zealand. Ancient jade that has been buried
for some time, appro¬' Iv called "buried jade,"
is of great interest to archaeologists.
"e
major commercial source of fine jadeite is Burma. The material
vcult to mine because of its great toughness. In times past
the red method was to heat the jade outcroppings and then
cool them nlv with cold water, the thermal "shock"
being sufficient to crack jade for easy removal. Today,
drills and other more modern raues are used. Boulders of
jade that have lain exposed for some ~ quire a brownish
"skin" due to weathering. The Chinese carvers
-aecialists in making use of this skin.
|
 |
 |
 |
| diamond
1 | 2 |
|
|
|
