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将霞石岩中的橄榄石(MgO=15.4%,FeO=8.5%)在约1个大气压的氮中完全熔融,在20~250℃过冷却条件下在2~10分钟内结晶。结晶的橄榄石的状态,当过冷却20℃时,为以玻璃为中心的包裹体自形晶,100℃左右时为链状细长骸晶,过冷却再加深时则成树枝状晶体。除树枝状晶体外,橄榄石b轴长度随结晶时间而增大,过冷却90℃在10分钟内结晶时长达70~80μm。在2分钟或4分钟内产生的自形晶与骸晶,呈Fo_(83)~Fo_(87)范围内的均质成分。产生均质的橄榄石时,在基质的玻璃上存在达100μm以上明显的浓度梯度。于是在
Olivine (MgO = 15.4%, FeO = 8.5%) in nepheline was completely melted in about 1 atmosphere of nitrogen and crystallized in 2 to 10 minutes under supercooling at 20 to 250 ° C. Crystalline olivine state, when the supercooling 20 ℃, for the glass-centered inclusions self-shaped crystal, about 100 ℃ when the chain-like elongated cristobalite, subcooling deepened into dendrite. In addition to the dendrites, the b-axis length of olivine increases with the crystallization time, reaching as submerged at 90 ° C for 70-80 μm in 10 minutes. The orthorhombic and skeletal cristae produced in 2 minutes or 4 minutes showed a homogenous composition in the range of Fo_ (83) ~ Fo_ (87). When homogenous olivine is produced, there is a significant concentration gradient above 100 μm on the matrix glass. So in