The microcline-sanidine stability relations
The microcline-sanidine stability relations
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微斜长石-胍胺稳定性关系
DOI：
10.1016/0016-7037(54)90058-7
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发表时间：
1954
影响因子：
5
通讯作者：
F. Laves
中科院分区：
文献类型：
--
作者：
J. R. Goldsmith;F. Laves
描述和讨论了介于KAlSi3O3的三斜和单斜晶化之间的结构中间态与合金中的有序无序。给出了微斜长石的X射线粉末衍射数据。中间状态是通过加热微斜长石远高于其转变为珊瑚碱的温度而产生的。这些状态不能在转变的大致范围内产生，无论是通过干热还是水热。然而，在水热条件下，微斜长石很容易转化为透长石，其温度远低于干燥状态下所需的温度。观察到的微斜长石水热转化为闪锌矿的最低温度为525℃。水热转化的发生机制不同于微斜长石在地表干燥加热时发生的简单扩散转化。讨论了这种转化的机理，包括微斜长石的溶解和闪锌矿的再沉淀。有人怀疑，在碱性长石系统中使用这种类型的转换来设定相变温度的有效性。
States that are structurally intermediate between the triclinic and monoclinic modifications of KAlSi3O3are described and discussed with relation to order-disorder in alloys. X-ray powder diffraction data on microcline are given. Intermediate states were produced by heating microcline well above the temperature of its inversion to sanidine. These states could not be produced in the approximate range of the transition, either by dry heating, or hydrothermally. Microcline is readily converted to sanidine, however, under hydrothermal conditions at temperatures well below those necessary in the dry state. The lowest temperature observed for the hydrothermal conversion of a microcline to sanidine was 525°C. The hydrothermal conversion takes place by a mechanism that differs from that of the simple diffusive transformation that occurs when microcline is heated dry aboveca. 1000°C. The mechanism of this conversion, which involves solution of microcline and re-precipitation of sanidine is discussed. Some doubt is cast on the validity of using this type of conversion in placing transformation temperatures in the alkali feldspar system.