Answers are grounded in this paper and cite their sources.
Measurements of birefringence, light scattering, second harmonic light generation and scattering have been made simultaneously at the α-β transition of quartz. They have been correlated with a coexistence zone (observed visually) of α and β phases in the hysteresis region and with Dauphine twinning.
No takes yet. Share an insight, caveat, or question.
Dolino et al. (1976) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: