Nephrite jade

FIuorosihca.tes, Compared to the simple sUicates, these crystals have more complex chain and sheet stmctures. Examples from nature iaclude hydrous micas and amphiboles, including hornblende and nephrite jade. In glass-ceramics, fluorine replaces the hydroxyl ion fluorine is much easier to iacorporate ia glass and also makes the crystals more refractory. Eour commercial fluorosUicate glass-ceramic compositions and thek properties are Usted ia Table 2. 

Jander, W., and J. Wurhrer (1938). Hydrothermal reactions (I) Formation of magnesium hydrosilicates. Zeit. Anorg u allgem Chemie 235 273-294. Jefferson, D. A., L. G. Hallinson, J. L. Hutchison, and J. M. Thomas (1976). Structural irregularities in nephrite jade an electron microscope study. Mater. Res. Bull. 11 1557-1562. 

Figure 10 A quadruple SiO chain defect in a matrix of double (Si04) chains of the amphibole type is shown (a) as a drawing of packing polyhedra and (b) occurring naturally in a crystal fragment of nephrite jade. In (b) the lower inset shows a superposition of the drawing in (a) at a reduced scale and the upper inset shows the computed image of such a defect (Reproduced by permission from Contrib. Mineral. Petrol., 1978, 66, 1)...

The first indication of these new linkages came from a study of nephrite jade. 

Crystals in which single or higher order chains of silica tetrahedra form the stractural backbone, like natural nephrite jade. The crystals tend to grow in acicular (needle-like) form in the glass. 

Jade Making jewelry and decorative objects Metal silicates Two varieties jadeite and nephrite... 

Jade, which has been valued in carving by eastern Asians for centuries, is generally one of two minerals—pyroxene or jadeite (NaAl(Si03)2) and the amphibole nephrite, Ca2(Fe+ )5 and/or Ca2(Mg+ )5(Si40n)2(0H)2. X-ray diffraction has shown the presence of triple chains in nephrite. 

Inosilicates contain single or double chains of tetrahedra. In a single chain structure, the Si to O ratio is 1 3, and in a double chain, it is 4 11. This structural class contains many common rock-forming minerals, including the amphibole and pyroxene groups. Both jade minerals, jadeite, and nephrite, fall within this group. 

Jade is the common name for gem-quality specimens of two distinctly different mineral species, jadeite and the massive variety of actinolite, called nephrite. The word jade is derived from the Spanish piedra deyjada, meaning stone of the flank. This refers to its popular use as a cure for diseases of the kidneys and liver. Other minerals that have been mistaken for jade, or used as jade imitations include green jasper (quartz), vesuvian (idocrase), massive grossular garnet, chloromelanite (a mixture of dark pyroxenes) (Table 2.10). 

The National Museum is considering buying a Maya plaque from Honduras that the seller claims to be jade. Jade is either jadite (sp gr 3.2 to 3.4) or nephrite (sp gr 3.0). What liquid would you recommend using to test whether or not the mask is jade ... 

The familiar jade analogy might be helpful. The functional role associated with jade picks out one physical substance (jadeite) in one circumstance, another physical substance (nephrite) in another circumstance. But even if all the realizers of the jade role are physical, that does not establish a physical ground for jade. 

Iridosmine = Iridium osmium alloy Fe-Cordierite = Sekaninaite Iserine (Nigrine) = Ilmenite + Rutile Isoplatinocopper = Hongshiite Isostannite = Kesterite-Ferrokesterite Jade = Jadeite (Nephrite)... 

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