34 Questions
What is the major chemical component of jadeite?
Species Pyroxene, and made primarily of sodium and aluminum
What is the characteristic of jadeite's transparency?
Ranges from opaque to transparent
What is the Mohs scale hardness of both jadeite and nephrite?
6.5-7
What is the most prized color of Jadeite in terms of value?
Pure green
What is the term used to describe the technique of enhancing jadeite's design by skilled carvers?
Qiao Se
What is the characteristic of nephrite's texture?
Tufted texture
What is the typical transparency of Nephrite?
Semitranslucent to opaque
What is the trace element responsible for the lavender color of Jadeite?
Manganese
What is the hardest type of jadeite to reach a high polish?
Coarse textured
What is the most commonly seen clarity feature in green nephrite?
Chromite crystals
In which type of environment does jadeite typically form?
Low-temperature, high-pressure
What is the most sought-after color of Nephrite?
White
What is the most common treatment used to enhance the color of jadeite?
Impregnation
What type of jadeite is technically completely natural?
Type A
What is the term used to describe colorless transparent jadeite?
Ice jade
What is the most popular style for mounting or stringing jadeite?
Cabochons
What is the term used to describe jadeite with clarity veins?
Floating blue flowers
What is the term used to describe rough nephrite extracted directly from a primary deposit?
Mountain jade
What is the common color of quartzite when it is dyed?
Whitish or Yellowish green
Which natural material has a similar greasy luster to jade?
Serpentine
What is the origin of Green Chalcedony, also known as Australian jade or Queensland jade?
Queensland, Australia
What is the typical appearance of Maw-sit-sit?
Saturated deep green to light green to black with black markings
What is the characteristic of Hydrogrossular garnet's color?
Green to bluish green
Which material is often used as a jadeite substitute due to its similar appearance?
Quartzite
What is the term used to describe stones with no visible interior?
Gambling stones
What is the most desirable color in the Chinese cultural tradition?
White
What is the term used to describe the type of jade that is tough enough to be carved into durable tools and weapons?
Omphacite
What is the name of the musical instrument made from omphacite in ancient China?
Qing
What is the name of the Chinese emperor who was impressed by jadeite and had it shipped to Beijing for fashioning into jewelry and carvings?
Qianlong
What is the year when China took over Burma, an area rich in jadeite deposits?
1784
What Jade grading type includes bleaching and impregnation ?
Type B
The grading for jadeite labeled as "Type C" includes what processes ?
Dyed
What type of crystal structure is jadeite ?
Fibrous polycrystalline aggregate
What it the top color for jadeite?
Pure green to slightly bluish or slightly yellowish green
Study Notes
Jadeite and Nephrite
- Jadeite's host rock is serpentinite, which is an igneous rock altered by metamorphic processes.
- Jadeite's major chemical components are sodium, aluminum, and silicon, and its major component is a pyroxene.
Crystal Structure and Characteristics
- Jadeite has a granular to fibrous polycrystalline aggregate crystal structure.
- Nephrite has a matted, tufted texture composed of minerals in the amphibole group.
- Jadeite's transparency ranges from opaque to transparent, with semitransparent being the most desirable.
- Jadeite's color variations may appear as veins or blotches, and skilled carvers can use these to enhance the design.
Nephrite Characteristics
- Black crystals of chromite are the most common clarity features in green nephrite.
- Nephrite's texture is very fine, and its color range includes green, white, black, yellow, gray, red, and rarely, blue.
Consumers and Market
- China is the largest consumer of jade, and the finest jadeite jewelry is often sold by auction houses.
- Jadeite and nephrite have a Mohs scale hardness of 6.5-7.
Color and Hue
- Jadeite's top value is pure green to slightly bluish or yellowish green, with an even, semitransparent vivid green being the most desirable.
- Nephrite's color, always semitranslucent to opaque, is described as "greasy".
- White nephrite is the most sought after, and different shades and brightness levels of white dramatically influence its price.
Chemical Composition and Forming Source
- Green jadeite's trace element is chromium, while lavender jadeite's trace element is manganese.
- Jadeite grows in high-pressure, low-temperature metamorphic environments.
Treatments and Cuttings
- Impregnation is the most common treatment for jadeite, using paraffin wax or clear polymer resin.
- Dyeing and heat treatment can be used to improve color, and GIA reports typically note "dyed", "impregnated", or "luster-enhanced".
- Rough jadeite might be fashioned as a "hololith", bangles, rings, and pendants in various shapes and styles.
Trade Names and Imitations
- Trade names for jadeite include "Imperial green", "grassy greens", "apple greens", "ice jade", and "floating blue flowers".
- Common imitations of jade include glass, plastic, idocrase, greenish amazonite, quartzite, marble, and serpentine.
History
- The ancient Chinese cultural tradition values white nephrite as a symbol of purity and nobility.
- Jadeite was used in Central America for tools, weapons, and ornamental carvings as early as 1500 BC.
- In the 16th century, jadeite was the most valuable treasure in the Aztec empire, and China took over Burma (now Myanmar) in 1784, gaining access to jadeite deposits.
Test your knowledge of jadeite and nephrite, two types of metamorphic rocks, and their formation processes. Learn about their chemical components, crystal structures, and how they are produced from serpentinite and other rocks.
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