中文摘要：

本文在28℃-1150℃温区对昆仑白玉进行高温原位X射线衍射实验,研究了升温和降温过程的物相变化,结果表明昆仑碧玉在常温下主相为Ca2Mg5Si8O22（OH）2,晶格参数a=9.818,b=18.047,c=5.275,α=90°,β=104.6°,γ=90°,空间群为C2/m,属于单斜晶系;升温过程中在800℃时少量杂质白云石（CaMg（CO3）2）分解,少量杂质滑石（Mg3[Si4O10]（OH）2）在900℃-1050℃分解,1000℃左右透闪石结构被破坏,存在形成CaMgSi2O6的两种机制,直到1150℃阳起石结构完全被破坏,最终产物中主要是透辉石CaMgSi2O6,还有少量CaSiO3,MgSiO3;降温过程的图谱表明这种高温相变是不可逆的.

英文摘要：

In this paper, Kunlun jade were used for the in situ high temperature X--ray diffraction （HT-XRD）studies of the heating and cooling process of the phase change, results show that the Kunlun jade at room temperature, the main phase of Ca2MgsSi8O22（OH）2, lattice Parameters a=9.818A, b=18. 047A, c=5. 275A, a=90°, β=104. 6°, γ=90°, space group C2/m, belongs to monoclinic system; the heating process a small amount of impurities at 800℃ Dolomite （CaMg （CO3）2） decomposition, a small amount of impurities in talc （Mgz [Si4O10] （OH）2） decomposition at 900℃--1050℃, 1000℃ actinolite about the structure is destroyed, there are two mechanisms for the formation of CaMgSi2O6, Until 1150℃ actinolite structure was completely destroyed in the final product is mainly diopside CaMgSi2O6, there are a few CaSiO3, MgSiO3 ; cooling process of the map show that the high temperature phase transition is irreversible.