Si pensa che la nefrite aiuti ad aumentare la salute e la resistenza, sia fisica che spirituale; è associata alla terra, alla prosperità e abbondanza...FONTE:
Nephrite is close relative of Jade and through the centuries there has been a lot of confusion between the two stones. The main practical difference is that Jade forms from the mineral Jadeite, whereas Nephrite forms from either Tremolite or Actinolite. In its pure state Nephrite is white, but the chemical impurities present when the stone forms cause a range of colors, from creamy white to yellow, brown, green, blue or black; the presence of iron is responsible for the rich green shades that we usually associate with Jade.
Nephrite has been mined and worked in China, India and South America for thousands of years. In the last century European deposits of Nephrite have been discovered in Switzerland, Poland, the Netherlands and Italy. Canada has what is believed to be the world's largest Nephrite deposits and produces a very hard, fine grade stone with excellent color.
The conditions necessary for Nephrite and Jade to form are rare, therefore the stones themselves are relatively rare and good quality specimens have a high market value. Although Nephrite and Jade are almost identical, Nephrite is a little more common and therefore tends to have a lower value than Jade. If you see Jade or Nephrite being sold with a trade name such as 'New Jade', 'Indian Jade', 'Burmese Jade' or 'Mexican Jade' it is either fake (Aventurine, Chrysoprase and dyed Agate are often passed off as Jade) or poor quality stone that has been dyed to enhance its color. Because Nephrite is tougher, more common and slightly less expensive than Jade it is the preferred material for carvings and pendants. As a general rule of thumb a Jade carving should be more expensive than a Nephrite carving, but be aware that Nephrite is usually labelled 'Jade' and sold at an inflated price.
Nephrite Jade is a tough and durable stone that has been associated with perfection and immortality for thousands of years. Jade is inextricably linked to ancient Chinese culture, where it was considered a sacred stone and esteemed above all others. Most Chinese Jade is Nephrite, called 'Yu' or 'Stone of China' and valued as highly as Diamonds are in the western world. The Supreme God in ancient Chinese mythology is the Jade Emperor Yu-hang-shang-ti and the Moon Hare ground Nephrite into his potion of immortality. A symbol of virtue and beauty, Nephrite had the power to protect against evil, accidents, malice and ill-wishing while also increasing serenity, peace of mind and balance.
In New Zealand the stone is known to the Native Maoris as Pounamu, 'Green Stone', and is believed to be a sacred healing stone. In 1997 a landmark legal ruling known as the Ngai Tahu Pounamu Vesting Act gave ownership of all naturally occurring pounamu back to the native peoples of New Zealand.
Working with Nephrite is believed to increase your health and endurance, both physically and spiritually, and encourages growth and progress in the material and magical worlds. A traditional Chinese potion made with a mixture of ground Nephrite, rice and dew water, was believed to strengthen the muscles, harden the bones, calm the mind, enrich the flesh and purify the blood. Modern crystal healers use Nephrite to strengthen the kidneys and promote elimination of toxins from the body. The stone has gained a reputation of being especially effective for healing kidney disorders.
Nephrite is an Earth stone, associated with growth, plenty and prosperity. Handling the stone every day is said to ensure that your wealth will increase and business owners are often advised to keep a piece in their cash register to help draw more money through their doors. Meditation with Nephrite can help to raise your prosperity consciousness, making you aware of the many blessings that surround you and receptive to new opportunities for growth and advancement.
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Da Wikipedia, l'enciclopedia libera.
La Nefrite è un minerale il cui nome deriva dal greco "nephron", cioè rene, a causa del suo utilizzo nell'antichità come amuleto nei confronti delle malattie dei reni.
Si tratta di una varietà di Actinolite che può presentarsi in moltissimi colori: giallastro, bruno, rossastro ma anche bianco o grigio, ma la più pregiata è la qualità verde. Può infine presentarsi maculata o striata. Con una lucentezza assolutamente simile a quella della Giadeite, una durezza comparabile ed una gamma di colori simile, viene con questa facilmente confusa e comunemente indicata col termine generico di giada.
Quando forma aggregati microcristallini ha una struttura fibrosa (come l'actinolite) che, unita all'elevata durezza, la rende ancora più tenace della giadeite. Quando invece è monocristallina è fragile.
Ha il medesimo impiego della giadeite, con la quale viene frequentemente confusa e genericamente commercializzata come giada.
Vengono realizzate triplette costituite da due cabochon incollati su una lamina di giada, utilizzando un collante di colore verde che rende il falso di difficile riconoscimento.
Si ricorre talvolta anche a colorazioni artificiali che ne migliorano l'aspetto.
Walter Schumann. Guida alle gemme del mondo, Zanichelli
Giada: introduzione alle culture utilizzatrici http://ostraka.forumfree.it/?t=54546601#entry445673800
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From Wikipedia, the free encyclopedia
Nephrite is a variety of the calcium and magnesium-rich amphibole mineral actinolite (aggregates of which also make up one form of asbestos). The chemical formula for nephrite is Ca2(Mg, Fe)5Si8O22(OH)2. 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 possess mainly grays and greens (and occasionally yellows, browns 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 can be found in a translucent white to very light yellow form which is known in China as mutton fat jade, in an opaque white to very light brown or gray which is known as chicken bone jade, as well as in a variety of green colours. Canada is the principal source of modern lapidary nephrite. 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 lapis nephriticus, which in turn is derived from Greek λίθος νεφρίτίκος; νεφρός λίθος, which means 'kidney stone' and is the Latin and Greek version of the Spanish piedra de ijada (the origin of "jade" and "jadeite"). Accordingly, nephrite jade was once believed to be a cure for kidney stones.
Besides the terms already mentioned, nephrite has the following synonyms and varieties: aotea, axe-stone, B.C. jade, beilstein, kidney stone, lapis nephriticus, nephrit, nephrita, pounamu, New Zealand greenstone, New Zealand jade, spinach jade (dark grayish green), and talcum nephriticus. Tomb jade or grave jade are names given to ancient burial nephrite pieces that have a brown or chalky white texture as a surface treatment.
Neolithic and Chalcolithic Europe
A lot of nephrite tools and amulets are known since the Early Neolithic (VII mill. BC) to the Late Chalcolithic (V mill. BC) on the Balkans (Bulgaria; Greece; Serbia; Croatia) from two or more unknown sources (there are a lot of serpentinized outcrops in these and other countries in the region). Such tools are found in the later Neolithic of Poland (from the most probable local source Jordanov), Sardinia (Italy) (unknown source) and Switzerland. Single or just a few finds of nephrite artefacts have been reported also from some other European countries.
Prehistoric and historic China
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.
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, and the exploitation of it is restricted and 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 were made of it; in particular the mere (short club), and the hei-tiki (neck pendant). These were believed to have their own mana, were handed down as valuable heirlooms, and often given as gifts to seal important agreements. It was also used for a range of tools such as adzes, as Māori had no metal tools.
In New Zealand English its normal name is "greenstone". Jade jewellery in Māori designs is widely popular with tourists – although much of the jade itself is now imported from British Columbia and elsewhere.
^ a b c d e f g h i j k l m n o p q r s t u v Gem Reference Guide. Gemological Institute of America. 1988. ISBN 0-87311-019-6.
^ Easby, Elizabeth Kennedy (1968). Pre-Columbian Jade from Costa Rica. New York: André Emmerich Inc.
Bale, Martin T. and Ko, Min-jung. Craft Production and Social Change in Mumun Pottery Period Korea. Asian Perspectives 45(2):159-187, 2006.
Laufer, Berthold, 1912, Jade: A Study in Chinese Archeology & Religion, Reprint: Dover Publications, New York. 1974.
Rawson, Jessica, 1975, Chinese Jade Throughout the Ages, London: Albert Saifer, ISBN 0-87556-754-1
Nephrite from Wyoming
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