Science. 1976 Oct 1;194(4260):105-7. doi: 10.1126/science.194.4260.105.
High sanidine, (K,Na)AlSi(3)O(8), transforms reversibly to a triclinic phase at high pressure. This is analogous to the high-temperature monalbite transformation. Disordered alkali feldspars of various compositions have unit-cell dimensions which are very similar at the transition (a = 8.30 A, b = 12.97 A, c = 7.14 A, and beta = 116.2 degrees ), indicating that the transformation is structurally controlled. Changes in temperature, pressure, and the sodium/potassium ratio cause similar structural variations: angles between adjacent, rigid tetrahedra vary to accommodate changing effective alkali cation sizes.
高温透长石（K,Na)AlSi(3)O(8)在高压下可可逆地转变为三斜相。这类似于高温单钠长石转变。各种成分的无序碱长石在相变时具有非常相似的晶胞尺寸（a = 8.30 A, b = 12.97 A, c = 7.14 A, 和 beta = 116.2 度），表明转变是结构控制的。温度、压力和钠/钾比的变化引起类似的结构变化：相邻刚性四面体之间的角度发生变化，以适应变化的有效碱金属阳离子大小。
