地球学报
地毬學報
지구학보
ACTA GEOSCIENTIA SINICA
2009年
5期
607-615
,共9页
独山玉%岩相学%矿物组合%成玉过程
獨山玉%巖相學%礦物組閤%成玉過程
독산옥%암상학%광물조합%성옥과정
Dushan Jjade%microscopic examination%mineral combination%iade-forming process
独山玉是迄今为止世界上唯一发现的达到宝石工艺要求的黝帘石化斜长岩质玉种,目前,有关独山玉的成玉过程研究还比较薄弱,本文在独山玉矿的野外考察和实验室标本观察的基础上,结合薄片的镜下鉴定研究发现:独山玉以脉状和多期多阶段产出;主要组成矿物有斜长石、黝帘石、角闪石,另有云母类矿物、榍石、葡萄石、方解石、电气石等次要矿物;独山玉常具有粒状结构、碎裂结构、残斑结构、熔蚀交代结构,似斑状结构,偶见针状变晶结构和糜棱结构;成玉的物理过程表现为辉长岩(独山玉的母岩)在韧性剪切应力下破裂和糜棱化,特别是由于剪切作用,斜长石脆塑性变形--细粒化,并遭受黝帘石化等作用形成玉脉.
獨山玉是迄今為止世界上唯一髮現的達到寶石工藝要求的黝簾石化斜長巖質玉種,目前,有關獨山玉的成玉過程研究還比較薄弱,本文在獨山玉礦的野外攷察和實驗室標本觀察的基礎上,結閤薄片的鏡下鑒定研究髮現:獨山玉以脈狀和多期多階段產齣;主要組成礦物有斜長石、黝簾石、角閃石,另有雲母類礦物、榍石、葡萄石、方解石、電氣石等次要礦物;獨山玉常具有粒狀結構、碎裂結構、殘斑結構、鎔蝕交代結構,似斑狀結構,偶見針狀變晶結構和糜稜結構;成玉的物理過程錶現為輝長巖(獨山玉的母巖)在韌性剪切應力下破裂和糜稜化,特彆是由于剪切作用,斜長石脆塑性變形--細粒化,併遭受黝簾石化等作用形成玉脈.
독산옥시흘금위지세계상유일발현적체도보석공예요구적유렴석화사장암질옥충,목전,유관독산옥적성옥과정연구환비교박약,본문재독산옥광적야외고찰화실험실표본관찰적기출상,결합박편적경하감정연구발현:독산옥이맥상화다기다계단산출;주요조성광물유사장석、유렴석、각섬석,령유운모류광물、설석、포도석、방해석、전기석등차요광물;독산옥상구유립상결구、쇄렬결구、잔반결구、용식교대결구,사반상결구,우견침상변정결구화미릉결구;성옥적물리과정표현위휘장암(독산옥적모암)재인성전절응력하파렬화미릉화,특별시유우전절작용,사장석취소성변형--세립화,병조수유렴석화등작용형성옥맥.
Dushan Jade is the only zoisitized plagioclase in the world which can meet iewelry technologic requirements,but the research on the formation process of Dushan Jade is very insufficient.Based on detailed field investigation and ore sample examination in laboratory,the authors identified opticaJ slices of Dushan Jade.The results show that Dushan Jade is characterized by the vein-like form and the multi-phase and multi-stage mineralization,with the minerals being mainly plagioclase,zoisite,hornblende,and subordinately mica,sphene,prehnite,tourmaline etc.Granular texture,cataclastic texture,porphyroid texture,corrosion texture,porphyritoid texture and,rarely,acicular texture and mylonitic texture can be seen in Dushan Jade.The iade-forming process finds expression in the shattering and mvlonitization of gabbro under the ductile shear stress.Brittle and plastic deformation and zoisitization of plagioclase resulted in the formation of Dushan Jade veins.