Nephrite | |
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General | |
Category | Inosilicate |
Formula (repeating unit) | Ca2(Mg,Fe)5Si8O22(OH)2 [1] |
Crystal system | monoclinic [1] |
Identification | |
Color | Translucent to opaque and often mottled. Light to dark green, yellow to brown, white, gray, black. [1] |
Crystal habit | massive [1] |
Fracture | splintery to granular [1] |
Mohs scale hardness | 6.0 to 6.5 [1] |
Luster | dull [1] |
Specific gravity | 2.95+0.15 −0.05 [1] |
Polish luster | vitreous to greasy [1] |
Optical properties | Double refractive with anomalous aggregate reaction [1] |
Refractive index | 1.606 to 1.632+0.009 −0.006 [1] |
Birefringence | usually not detectable [1] |
Pleochroism | none [1] |
Ultraviolet fluorescence | inert [1] |
Absorption spectra | Vague line may be present at 500 nm, but rarely any lines. Rarely, in stones of exceptional gem quality, vague lines in the red part of the spectrum may be seen. [1] |
Nephrite is a variety of the calcium, magnesium, and iron-rich amphibole minerals tremolite or actinolite (aggregates of which also make up one form of asbestos). The chemical formula for nephrite is Ca 2(Mg, Fe)5 Si 8 O 22(OH)2. [1] It is one of two different mineral species called jade. The other mineral species known as jade is jadeite, which is a variety of pyroxene. While nephrite jade possesses mainly grays and greens (and occasionally yellows, browns, black or whites), jadeite jade, which is rarer, can also contain blacks, reds, pinks and violets. Nephrite jade is an ornamental stone used in carvings, beads, or cabochon cut gemstones. Nephrite is also the official state mineral of Wyoming.
Nephrite can be found in a translucent white to very light yellow form which is known in China as mutton fat jade, [1] in an opaque white to very light brown or gray which is known as chicken bone jade, [1] as well as in a variety of green colors. Western Canada is the principal source of modern lapidary nephrite. [2] Nephrite jade was used mostly in pre-1800 China as well as in New Zealand, the Pacific Coast and Atlantic Coasts of North America, Neolithic Europe, and southeast Asia.
The name nephrite is derived from the Latin lapis nephriticus, which in turn is derived from the Ancient Greek λίθος νεφριτικός (líthos nephritikós) or νεφρός λίθος (nephrós líthos), which means "kidney stone" and is the Latin and Greek version of the Spanish piedra de ijada (the origin of jade and jadeite). [3] Accordingly, nephrite jade was once believed to be a cure for kidney stones.[ citation needed ]
Besides the terms already mentioned, nephrite has the following synonyms and varieties: axe-stone, B.C. jade, Beilstein, kidney stone, lapis nephriticus, nephrite, nephrite, pounamu , New Zealand greenstone, [1] New Zealand jade, [1] spinach jade (dark grayish green), [1] and talcum nephriticus. Tomb jade or grave jade are names given to ancient burial nephrite pieces with a brown or chalky white texture as a surface treatment. [1]
A lot of nephrite tools and amulets are known since the Early Neolithic (7th millennium BC) to the Late Chalcolithic (5th millennium BC) on the Balkans (mainly Bulgaria; also in Greece, Serbia, Croatia) from two or more unknown sources — Balkan "nephrite culture." [4] Such tools are found in the Later Neolithic of Poland (from the most probable local source Jordanów), Sardinia (Italy) (unknown source) and Switzerland. [4] Single or just a few finds of nephrite artifacts are also reported from some other European countries.
During Neolithic times, the key known sources of nephrite jade in China for utilitarian and ceremonial jade items were the now depleted deposits in the Ningshao area in the Yangtze River Delta (Liangzhu culture 3400–2250 BC) and in an area of the Liaoning province in Inner Mongolia (Hongshan culture 4700–2200 BC). Jade was used to create many utilitarian and ceremonial objects, ranging from indoor decorative items to jade burial suits. Jade was considered the "imperial gem." From about the earliest Chinese dynasties until present, the jade deposits in most use were from the region of Khotan in the Western Chinese province of Xinjiang (jade deposits from other areas of China, such as Lantian, Shaanxi, were also in great demand). There, white and greenish nephrite jade is found in small quarries and as pebbles and boulders in the rivers flowing from the Kuen-Lun mountain range northward into the Takla-Makan desert area. River jade collection was concentrated in the Yarkand, and the White Jade (Yurungkash) and Black Jade (Karakash) Rivers in Khotan. From the Kingdom of Khotan, on the southern leg of the Silk Road, yearly tribute payments consisting of the most precious white jade were made to the Chinese imperial court and there transformed into objets d'art by skilled artisans, as jade was considered more valuable than gold or silver.
Carved nephrite jade was the main commodity trade during the historical Maritime Jade Road, an extensive trading network connecting multiple areas in Southeast and East Asia. The nephrite jade was mined in east Taiwan by animist Taiwanese indigenous peoples and processed mostly in the Philippines by animist indigenous Filipinos. Some were also processed in Vietnam, while the peoples of Malaysia, Brunei, Singapore, Thailand, Indonesia, and Cambodia also participated in the massive animist-led nephrite jade trading network, where other commodities were also traded. Participants in the network at the time had a majority animist population. The maritime road is one of the most extensive sea-based trade networks of a single geological material in the prehistoric world. It was in existence for at least 3,000 years, where its peak production was from 2000 BCE to 500 CE, older than the Silk Road in mainland Eurasia. It began to wane during its final centuries from 500 CE until 1000 CE. The entire period of the network was a golden age for the diverse animist societies of the region. [5] [6] [7] [8]
Nephrite jade in New Zealand is known as pounamu in the Māori language and is highly valued, playing an important role in Māori culture. It is considered a taonga , or treasure, and therefore protected under the Treaty of Waitangi. The exploitation of it is restricted to the Ngāi Tahu iwi (tribe) [9] and it is closely monitored. The South Island of New Zealand is Te Wai Pounamu in Māori — 'The [land of] Greenstone Water' — because that is where it occurs.
Weapons and ornaments are made of it; in particular the mere (short club) and the hei-tiki (neck pendant). These are believed to have their own mana (prestige), are handed down as valuable heirlooms, and often given as gifts to seal important agreements. It has also been used for a range of tools such as adzes and was used to make nails used in construction, as Māori culture had no metalworking before European contact.
Commonly called "greenstone," jade jewellery in Māori designs is widely popular with tourists. Stone is often imported from Canada, China and Siberia, and Ngāi Tahu runs a pounamu certification scheme to verify the authenticity of New Zealand stone.
Actinolite is an amphibole silicate mineral with the chemical formula Ca2(Mg4.5–2.5Fe2+0.5–2.5)Si8O22(OH)2.
Jade is an umbrella term for two different types of decorative rocks used for jewelry or ornaments. Jade is often referred to by either of two different silicate mineral names: nephrite, or jadeite. Nephrite is typically green, although may be yellow, white or black. Jadeite varies from white or near-colorless, through various shades of green, to lavender, yellow, orange, brown and black. Rarely it may be blue. Both of these names refer to their use as gemstones, and each has a mineralogically more specific name. Both the amphibole jade (nephrite) and pyroxene jade are mineral aggregates (rocks) rather than mineral species. Nephrite was deprecated by the International Mineralogical Association as a mineral species name in 1978. The name "nephrite" is mineralogically correct for referring to the rock. Jadeite, is a legitimate mineral species, differing from the pyroxene jade rock. In China, the name jadeite has been replaced with fei cui, the traditional Chinese name for this gem that was in use long before Damour created the name in 1863.
The hei-tiki is an ornamental pendant of the Māori of New Zealand. Hei-tiki are usually made of pounamu (greenstone), and are considered a taonga (treasure) by Māori. They are commonly called tiki by New Zealanders, a term that originally refers to the first mortal.
Jadeite is a pyroxene mineral with composition NaAlSi2O6. It is hard (Mohs hardness of about 6.5 to 7.0), very tough, and dense, with a specific gravity of about 3.4. It is found in a wide range of colors, but is most often found in shades of green or white. Jadeite is formed only in the subduction zones of continental margins, where rock undergoes metamorphism at high pressure but relatively low temperature.
The mere is a type of short, broad-bladed weapon in the shape of an enlarged tear drop. It was used to strike/jab an opponent in the body or the head, usually made from nephrite jade. A mere is one of the traditional, hand to hand, one-handed weapons of the indigenous Māori of New Zealand, and a symbol of chieftainship.
The tradition of Korean jade carving dates back to neolithic finds along the Namgang river basin in Gyeongju. Jade rings and accessories made from both nephrite and jadeite were worn by the higher classes of society, especially women, from the three kingdoms period and reached their peak in the Joseon dynasty, the golden age of jadework. Carved jade artifacts found in Silla dynasty tombs appear to be made from jade originating from Japan and Taiwan, suggested sea trade of jade existed prior to the 5th century AD. Korean jadework often includes Buddhist motifs, cicadas, and small peanut-shaped or comma-shaped good luck talismans, as well as larger-scale architectural pieces. A gold crown featuring 58 hanging jade pendants and a gold girdle with 13 jade pendants were both found in the Silla-era tomb of an unknown king, called Cheonmachong, first excavated in 1973.
Bowenite is a hard, compact variety of the serpentinite species antigorite (Mg3(OH)O4Si2O5). Classed as a semi-precious gemstone, it has been used for tools, weapons and jewellery by the Māori in New Zealand, and for jewellery by Fabergé. Deposits are found in several places around the world including Afghanistan, China, New Zealand, South Africa and the United States. It typically ranges in colour from dark green to light olive green, and in shades approaching yellow. Bowenite was named by James D. Dana in 1850 after George T. Bowen, who analyzed it in 1822.
The use of jade in Mesoamerica for symbolic and ideological ritual was highly influenced by its rarity and value among pre-Columbian Mesoamerican cultures, such as the Olmec, the Maya, and the various groups in the Valley of Mexico. Although jade artifacts have been created and prized by many Mesoamerican peoples, the Motagua River valley in Guatemala was previously thought to be the sole source of jadeite in the region.
Chinese jade refers to the jade mined or carved in China from the Neolithic onward. It is the primary hardstone of Chinese sculpture. Although deep and bright green jadeite is better known in Europe, for most of China's history, jade has come in a variety of colors and white "mutton-fat" nephrite was the most highly praised and prized. Native sources in Henan and along the Yangtze were exploited since prehistoric times and have largely been exhausted; most Chinese jade today is extracted from the northwestern province of Xinjiang.
Most information about Taiwan before the arrival of the Dutch East India Company in 1624 comes from archaeological finds throughout the island. The earliest evidence of human habitation dates back 20,000 to 30,000 years, when lower sea levels exposed the Taiwan Strait as a land bridge. Around 5,000 years ago, farmers from what is now the southeast coast of China settled on the island. These people are believed to have been speakers of Austronesian languages, which dispersed from Taiwan across the islands of the Pacific and Indian Oceans. The current Taiwanese aborigines are believed to be their descendants.
The Arahura River, for a time called the Brunner River after the explorer Thomas Brunner, is a river located on the West Coast of the South Island of New Zealand. In 1846 Brunner and Heaphy sketched and described a Māori settlement they called Araura [sic] (Arahura).
Greenstone is a common generic term for valuable, green-hued minerals and metamorphosed igneous rocks and stones which early cultures used in the fashioning of hardstone carvings such as jewelry, statuettes, ritual tools, and various other artifacts. Greenstone artifacts may be made of greenschist, chlorastrolite, serpentine, omphacite, chrysoprase, olivine, nephrite, chloromelanite among other green-hued minerals. The term also includes jade and jadeite, although these are perhaps more frequently identified by these latter terms. The greenish hue of these rocks generally derives from the presence of minerals such as chlorite, hornblende, or epidote.
Hardstone carving, in art history and archaeology, is the artistic carving of semi-precious stones, such as jade, rock crystal, agate, onyx, jasper, serpentinite, or carnelian, and for objects made in this way. Normally the objects are small, and the category overlaps with both jewellery and sculpture. Hardstone carving is sometimes referred to by the Italian term pietre dure; however, pietra dura is the common term used for stone inlay work, which causes some confusion.
The jade trade in Myanmar consists of the mining, distribution, and manufacture of jadeite—a variety of jade—in the nation of Myanmar (Burma). The jadeite deposits found in Myanmar's northern regions are the source of the highest quality jadeite in the world, noted by sources in China going as far back as the 10th century. Chinese culture places significant weight on the meaning of jade; as their influence has grown in Myanmar, so has the jade industry and the practice of exporting the precious mineral.
Joe Sheehan is a stone artist and jeweller who works primarily in pounamu.
Philippine jade culture, or jade artifacts, made from white and green nephrite and dating as far back as 2000–1500 BC, have been discovered at a number of archaeological excavations in the Philippines since the 1930s. The artifacts have been both tools like chisels and ornaments such as lingling-o earrings, bracelets, and beads.
Waipounamu Māori are a group of Māori iwi at or around the South Island of New Zealand. It includes the iwi (tribe) of Ngāi Tahu and the historical iwi of Kāti Māmoe and Waitaha, who occupy the island except for its most northern districts. It also includes Te Tau Ihu Māori iwi, such as Ngāti Toa, Te Atiawa o Te Waka-a-Māui, Ngāti Apa ki te Rā Tō, Rangitāne, Ngāti Kuia, Ngāti Rārua, Ngāti Kōata and Ngāti Tama.
Lingling-o or ling-ling-o are a type of penannular or double-headed pendant or amulet that have been associated with various late Neolithic to late Iron Age Austronesian cultures. Most lingling-o were made in jade workshops in the Philippines, and to a lesser extent in the Sa Huỳnh culture of Vietnam, although the raw jade was mostly sourced from Taiwan.
Pounamu is a term for several types of hard and durable stone found in the South Island of New Zealand. They are highly valued in New Zealand, and carvings made from pounamu play an important role in Māori culture.
Yupei is a generic term for jade pendants. Yupei were popular even before Confucius was born. Jade culture is an important component of Chinese culture, reflecting both the material and spiritual culture. Jade is deeply ingrained in Chinese culture and played a role in every aspect of social life; it is also associated with positive qualities and aspects such as purity, excellence, and harmony.Jade is even more valued than gold in Chinese culture. The history of the art of jade carving in China to make ornaments, including dress ornaments, extends back to before 5000 BC. Ancient Chinese held even greater importance to yupei after it was regarded as a moral integrity by Confucius. Yupei could be used as belt or waist ornaments and as necklaces which appeared as early as the Liangzhu culture. Strings of jade pendant are also used to decorate headwear, such as the mianguan.