Stone Info_Jade PDF

***Jade ( Jadeite & Nephrite) ***** LARGEST CONSUMERS : China, The finest jadeite jewelry is often sold by auction houses. MOHS SCALE: 6.5- 7 for both jadeite and nephrite VARIETY/SPECIES/GROUP: pryoxene COLOR/HUE RANGE/VALUE: Jadeite: top value are pure green to a slightly bluish or slightly yellow...

***Jade ( Jadeite & Nephrite) ***** LARGEST CONSUMERS : China, The finest jadeite jewelry is often sold by auction houses. MOHS SCALE: 6.5- 7 for both jadeite and nephrite VARIETY/SPECIES/GROUP: pryoxene COLOR/HUE RANGE/VALUE: Jadeite: top value are pure green to a slightly bluish or slightly yellowish green- top color is an even, semitransparent vivid green, more readily available are yellowish greens—bluish greens, grayish greens, and blackish greens-darker tones are more valuable than lighter tonescolor uniformity is crucial to jadeite quality -Additional Colors: lavender, red, orange, yellow, brown, white, black, and gray, black is actually very dark green only visible under very strong transmitted light. Lavender second most valued color, light purple hue is most prized when it’s highly saturated. Nephrite: green, white, black, yellow, gray, red, and, rarely, blue; white being the most sought after- color, always semitranslucent to opaque, "greasy" is the top way to describe nephrite transparency and luster Different shades and brightness levels of white dramatically influence nephrite’s price CHEMICAL COMPOSTION: Green Jadeite: trace element is chromium, Lavender Jadeite: trace element manganese FORMING SOURCE: grows in high-pressure, low-temperature metamorphic environments. jadeite’s host rock is serpentinite which is an igneous rock that was altered by metamorphic processes, igneous rocks and fluids rich in sodium, aluminum, and silicon are jadeites major chemical components,Jadeite’s major component is a pyroxene Nephrite is a rock composed mainly of minerals in the amphibole group with fibrous crystals that interlock in a matted, tufted texture, is produced when serpentinite contacts calcium-rich silicon-containing rocks CRYSTAL STRUCTURE: aggregate (rock composed of interlocking mineral grains or crystals) granular to fibrous polycrystalline aggregate POSSIBLE PHENOMENA: jadeite (N/A) CLARIETY CHARACTERISTIC: transparency ranges from completely opaque to transparent, with semitransparent being the best, (Good transparency can sometimes compensate for imperfect color), color variations might appear as veins or blotches, called mottling, skilled carvers may use these variations to enhance the design-a technique called “Qiao Se” in Chinese Texture: very fine texture is called "old mine", coarser texture is described as "new mine", able to take a high polish with coaser texture being harder to reach a high polish Nephrite: Black crystals of chromite are the most commonly seen clarity features in green nephrite. COMMON TREATMENTS: 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,GIA reports typically note “dyed,” “impregnated,” or “luster-enhanced.” when referring to treatments -Treatment grading: Type A jadeite is technically completely natural, Type B jadeite is bleached and impregnated, Type C jadeite is dyed COMMON CUTS: rough jadeite might be fashioned as a "hololith", bangles, rings, and pendants in various shapes and styles. Cabochons, carved pendants, and beads are the most popular styles for mounting or stringing, Artistry and craftsmanship are particularly important in an evaluation of jade carvings Nephrite- green nephrite jewelry, decorations, and other luxury productsbangles and pendants are the most popular items,r ough material is also processed to create decorations such as luxury tiles, lampshades, and more. TRADES NAMES: "Imperial green" "grassy greens"or "apple greens", bluish greens, grayish greens, and blackish greens. “ice jade.” (colorless transparent jadeite) “floating blue flowers.”(describing clarity veins), “Burmese jade” (when coming from Myanmar) “Fei Cui.” "Mountain Jade" rough nephrite extracted directly from a primary deposit "River Jade" rough from alluvial deposits usually located along the rivers. "Polar Jade" Polar mine in northern British Columbia, is the trade’s best-known green nephrite COUNTRIES OF ORIGIN: Myanmar is a major source, especially of fine-quality material. Other jadeite sources include Guatemala, Russia, Japan, and the US state of California, Hpakant is the center of the jadeite mining district and it follows the path of the Uru and Hwe rivers. Nephrite: The main sources are British Columbia, Canada; Xinjiang Province, China; East Sayan, near Russia’s Lake Baikal; and Chuncheon, Korea. Other sources with very limited or no production include New Zealand, South Australia, China’s Guangxi Province, Val Malenco in Italy, and Wyoming in the US. China’s Xinjiang Uygur Autonomous Region famous mutton-fat jade, which is top-quality white nephrite. Green nephrite production comes mainly from the Manasi River Valley in the southern Junggar Basin. Mount Ogden and Kutcho mines are the two most productive green nephrite sources. In terms of production, British Columbia is the world’s largest nephrite supplier today. MAIN SYNTHETIC PROCESS: n/A COMMON IMITATION MATERIAL: glass and plastic are still the most common imitations on the market imitations can be assembled, coated, dyed, or made of any of a variety of materials, Natural material imitation include: Idocrase, Greenish Amazonite & Quartzite: quartzite is the most common and one of the most effective, usually whitish or slightly yellowish it's calmly dyed green or purple Marble: White marble can be confused with white nephrite, while dyed marble is often used as a jadeite substitute,tends to have coarser texture than quartzite and jade Serpentine: metamorphic rock, similar greasy luster, yellowish green color and hardness for carving, sources, including northern China, Korea, and Italy, readily available and cheaper then jade Green Chalcedony: different shades of green, including the yellowish green variety called chrysoprase, Its color, fine texture, and transparency, mined in Queensland, Australia and marketed as Australian jade or Queensland jade. Maw-sit-sit: vivid green aggregate of several different minerals in varying amounts. mined near Tawmaw, Myanmar, saturated deep green to light green to black uniformly mottled, streaked, or spotted, markings are usually black, today it's not often seen on the market. Hydrogrossular garnet: an aggregate,its green to bluish green colors, and is a common presence on the market, transparency, mottled appearance, and color are similar to some fine-quality jadeite. Trade terms for hydrogrossular include Transvaal jade and African jade. CUTTING/TRADING CENTER: Guangzhou, Jieyang, Sihui, and Pingzhou are the four major jade manufacturing and trading townsmajor jadeite trading hubs are located near the border with Kachin State, Yingjiang, Tengchong, and Ruili. Jieyang- claims the title of “jade capital of Asia”specializes in medium- to high-quality jadeite Guangzhou- focuses more on trade because of its geographical location Sihui - famous for jadeite carving Pingzhou- called the “hometown of jade bangles.” Nephrite: Production from British Columbia is shipped to Guangdong, China, for processing. Most nephrite rough from Siberia enters China through its northern border ports and then goes to Guangdong for manufacturing. BUYING: buyers rely on show points or windows to determine a materials worth, the visible interior the higher the price point can be,“gambling stones,” or stones with no window are priced at a discount HISTORY: “omphacite jade.” (All other colors of omphacite, most commonly black, white, and blue, are simply called “omphacite", tough enough to be carved into durable tools and weapons, They used it to make a musical instrument called “qing -Ancient Chinese cultural tradition, which holds that white represents purity and nobility, make white the most desirable color nephrite -trading centers, auctions, and retail stores, nephrite also plays an important role in the Chinese antique market since many ancient artifacts are made of nephrite. As early as 1500 BC, people in Central America used jadeite for tools, weapons, and ornamental carvings such as ceremonial masks. By the early 16th century, when Cortez invaded the Aztec empire, jadeite was the most valuable treasure Montezuma had to offer. 1784, China took over Burma (now Myanmar), an area rich in jadeite deposits. China’s emperor, Qianlong, was impressed by the "new jade" and had it shipped to Beijing for fashioning into exquisite jewelry and carvings.