控温梯度及时间对合成翡翠品质的影响

Effect of Temperature Control Gradient and Time on the Quality of Synthetic Jadeite

合成翡翠是由定量配比的非晶质粉料在特定高压高温环境下生长形成的,生长条件对合成翡翠的品质具有重要影响。基于合成翡翠的高温高压生长环境,增加不同控温梯度和控温时间,研究低温保温阶段对合成翡翠品质的影响。实验过程所有合成翡翠的合成压力均为4.5 GPa,采用由高温固相法制备的100目粉料,对比在高温温度(1100℃和1400℃)、保温时间180 mins时,分别增加不同的低温保温温度和保温时间(950℃、10 mins和1100℃、30 mins)的合成翡翠品质;采用由高温固相和溶胶凝胶法制备的140目粉末,对比在高温保温温度1100℃、保温时间180 mins的条件下,增加3种不同低温保温时间(低温温度固定为950℃,1 min、10 mins和30 mins)后的合成翡翠品质。结果显示,不同条件下生长的合成翡翠均为多晶质体,呈均匀绿色,其宝石学性质、紫外-可见光谱和红外光谱与天然翡翠基本一致。显微薄片观察表明,所有合成翡翠样品均为粒柱状结构,扫描电子显微镜观察表明增加低温保温阶段(1100℃,30 mins)后,合成翡翠样品发育长针状不定向晶体,晶粒间隙变小,且低温保温时间越长,晶粒间隙越小。合成翡翠过程中,增加一定的低温保温时间,可获得更优品质的合成翡翠。

Synthetic jadeite is grown from quantitatively proportioned amorphous powder in a high-pressure high-temperature(HPHT)environment.The growing environment greatly impacts the quality of the synthetic jadeite.In this paper,before applying the traditional HPHT growing stage,we added different low-temperature growing stages and investigated the effect of the low-temperature growing stage on the quality of the synthetic jadeite.The pressure of all growing environments was fixed to 4.5 GPa.Using 100 mesh powder prepared by high-temperature solid-state method,we compared the quality of the synthetic jadeites that both grown in high-temcperature(1100℃and 1400℃)environments with 180 mins preservation time,but have different low-temperature and presenation time(950℃,10 mins and 1100℃,30 mins).Using 140 mesh powder prepared by high-temperature solid-state method and sol-gel method,we compared the quality of synthetic jadeites that both grown in a high-temperature of 1100℃with 180 mins preservation time,but have different low-temperature preservation times at a fixed low-temperature of 950℃.The results showed that the synthetic jadeite grown in different environments were all polycrystalline and with uniform green colour,and their gemmological properties,UV-Vis absorption spectra and FTIR reflection spectra were consistent with those of natural jadeite.The microslice images of the synthetic jadeite showed that all the synthetic jadeite had a granular-columnar structure.The scanning electron microscope(SEM)images showed that the synthetic jadeite developed long needle-like non-directional crystals and smaller grain gaps with adding low-temperature preservation stages(1100℃,30 mins),and the longer the low-temperature preservation stage,the smaller the grain gap would be.In conclusion,synthetic jadeite with better quality could be obtained by adding a low-temperature preservation stage in the process of growing synthetic jadeite.