sanidine

CONT: Dans les roches volcaniques récentes, on trouve la sanidine, orthose craquelée, déformée, transparente, à l'éclat vitreux, voisin de celui du quartz.
OBS: Formule chimique : (K,Na)AlSi[indice 3]O[indice 8]

OBS: [Sanidine] is a highly disordered, monoclinic form, occurring in clear, glassy, often tabular crystals embedded in unaltered acid volcanic rocks such as trachyte; it appears to be stable under equilibrium conditions above approximately 500°C. Sanidine forms a complete solid-solution series with high albite, and some sodium is always present.
OBS: Chemical formula: (K,Na)AlSi[subscript 3]O[subscript 8]

OBS: [La sanidina] se encuentra en ciertas rocas volcánicas relativamente recientes.
OBS: Fórmula química: (K,Na)AlSi[subíndice 3]O[subíndice 8]