You will find that when cutting Nephrite and Jadeite, Jadeite takes longer and wears the cutting material more. Jadeite can be used to shape Nephrite tools, whereas Nephrite is useless against Jadeite. Put Jadeite and Nephrite, steel, and Quartz in a tumbler, I have. The Nephrite, steel, and Quartz will be ground to about half their respective mass, whereas Jadeite looses only a small fraction.
Try scratching Jadeite with Nephrite, you cannot, but Jadeite easily scratches Nephrite. This is because Jadeite's interlocking micro-crystalline structure prevents anything from penetrating, or breaking it. While it is true that Nephrite is relatively tough, and was used for tools, it is not as tough as Jadeite. The article correctly states that Nephrite is tougher than a diamond, but steel and Jadeite likewise are tougher than diamonds.
Although Jadeite's being harder does not mean it is tougher, it does add to it's tough attributes. Try cutting or grinding Nephrite and then Jadeite with any medium, diamond included,
Bullets, arrow tips, and spear-heads have their effectiveness determined by the density, and hardness of the projectile, and in this respect Jadeite comes on to also, with its significantly higher specific gravity.
While it is true that Jadeite is more readily fusible than Nephrite, this attribute contributes to its brighter and deeper polish. Nephrite is closely related to Asbestos, another Amphibole, which also does not fuse readily, but is not considered to be very tough.
Nephrite, has a lower specific gravity than Jadeite, 2.96 – 3.1 compared to Jadeite’s 3.3 – 3.5. Nephrite’s hardness ranges 6 – 6.5, whereas Jadeite is 6.5 – 7. Jadeite could be used to sharpen Nephrite and quartz, so it was used in the making of tools.
Since Jadeite is based upon interlocking micro-crystalline crystals, it is harder to cut than Nephrite, even while using diamond blades. When Jadeite, Nephrite, and quartz, are tumbled together, only the Jadeite survives, with the others loosing up to half of their mass.
Large sections of Jadeite tend to be more brittle than Nephrite, so Nephrite is probably a better material for making a sword. There were no indigenous swords in North America though, weapons consisting of adzes, daggers, spears and arrows.
Jadeite is superior for adze, and knifes since it is heavier, and harder. Many archeological finds include Jadeite adzes and black Jadeite (Chloromelanite) adzes , the more well know being from Joel Castanza. See: http://www.theaaca.com/lithnics/Jade.html
In Mexico, in Central America and in the northern part of South America, objects of jadeite are common. The Kunz votive adze from Oaxaca, in Mexico, is now in the American Museum of Natural History, New York. At the time of the Spanish conquest of Mexico amulets of green stone were highly venerated, and it is believed that jadeite was one of the stones prized under the name of chalchihuitl. Probably turquoise was another stone included under this name, and indeed any green stone capable of being polished, such as the Amazon stone, now recognized as a green feldspar, may have been numbered among the Aztec amulets. Dr Kunz suggests that the chalchihuitl was jadeite in southern Mexico and Central America, and turquoise in northern Mexico and New Mexico. He thinks that Mexican jadeite may yet be discovered in places (Gems and Precious Stones of Mexico, by (~. F. Kunz: Mexico, 1907). From: http://65.1911encyclopedia.org/J/JA/JAEN.htm
JADEITE AXE is superb and undamaged! Professor (ret) Gerry Johnson of The College Of William And Mary has determined this axe to be Jadeite--similar Jadeite(black-green) is found in Costa Rica and was used by Mayan and other regional peoples--can this piece prove that extensive trading occured between North and Central America? A spectacular Olmec Jadeite Mask is shown on page 246 of "The Smithsonian Book Of North American Indians" by Philip Kopper, Smithsonian Press,1986..."a Jade mask from about nine centuries before Christ..." The unmistakable material similaries between this fine Jadeite axe and the mask are evidence supporting the existance of far-flung trading routes in the ancient Americas. From: http://www.angelfire.com/va/mobjackrelics/
One incidence of a British Columbia Fraser Canyon jadeite adze. The rare native copper items have been attributed to the Lake Superior region. From: http://www.civilization.ca/archeo/hnpc/npvol26e.html
A ceremonial adze known as the "Kunz ax", green jadeite, from the British Museum, London, of the Olmec "were-jaguar", which combined features of a human and a jaguar. (The name is a parallel construction with werewolf.) As described by Michael Coe and Rex Koontz (2002: 64), Olmec were-jaguars are usually depicted as "somewhat infantile throughout life, with the puffy features of small, fat babies, snarling mouths, toothless gums or long, curved fangs, and even claws. The heads are cleft at the top...". See: http://www.mesoweb.com/olmec/ceremonial_adze.html
Giddings' doctoral dissertation on the Arctic Woodland Culture stands as an example of the integration of paleo-environmental, archaeological, and geological data to provide an understanding of prehistoric human behavior. Giddings (1952: 116) viewed the Arctic Woodland Culture as relying on fishing, small marine mammal hunting, and caribou hunting depending on the season, abundance, and distribution of these econdmic'resources. The culture existed in the forested streams, and along the coast of northwest Alaska for a period of over 700 years, roughly from A.D. 1250 to the nineteenth century. l In artifactual terms, it was composed of the following items, in which sea mammal hunting implements were missing because Giddings could not stylistically separate them from those used by coastal dwelling groups.