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Study Of Gemological Mineralogy Of Green Nephrite From South Australia, Australia

Posted on:2015-02-03Degree:MasterType:Thesis
Country:ChinaCandidate:X H ZhaoFull Text:PDF
GTID:2250330428969697Subject:Gemology
Abstract/Summary:PDF Full Text Request
The Australian green nephrite is not popular in market share of the world,for itstoo deep colour and poor transparency. On the other hand,the Australian greennephrite,especially the one from Cowell,is large in volume,good in quality,andcompact in structure. The Australian green nephrite is usually deep green to black,and can be a good choice of sculpture. But cause of the lack of market demand,research on it was nearly none.To study gemological mineralogy and structure of green nephrite from Cowell,Australia,this thesis based on SEM, EMPA, XRD, IR, DTA and LA-ICP-MStests.The main mineral of the green nephrite from Cowell,South Australia,isactinolite, even the amphibole asbestine. Associated minerals are chlorite,chromite,apatite and graphite. Special need to mention is barite and monazite,whichwere never found in nephrite from other origins.Cowell green nephrite is cryptocrystalline, including felt-like blastic texture,fiber blastic texture,and radial blastic texture and vein-like blastic texture.The scanning electricity mirror result suggests that felt-like blastic texture has thebest quality and the strongest tenacity, and has the list possibility to break up,because the crack in the felt-like in shape structure is the hardest to expand. Felt-likeblastic texture is better than fiber blastic texture. The weakest texture has the highestdegree of order. The cracks in this kind of texture are most easily to expand. Thisfeature makes the nephrite hard to cut and process.The XRD shows that the surrounding rock of the nephrite mainly consists oftremolite with mica and minor carbonatite.The Cowell deposit formed between0.20to0.30GPa,the gradual coolingprocess was retrogressive metamorphic that from450to300℃.
Keywords/Search Tags:Cowell, green nephrite, structure
PDF Full Text Request
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