Summary: Differential thermal analysis of a rapidly reversible transition in carnegieite to 7 kbar shows the transition temperature increases from < ˜ 707 °C (on heating) at 1 bar with initial slope ≈ 8·0 deg kbar⁻¹ and anomalous curvature (d²T/dp² > 0), with hysteresis between heating and cooling signals that decreases with pressure. DTA of rapidly reversible transitions in nepheline shows the very subtle transition near 185 °C (on heating) at 1 bar decreases with pressure to ≈ 170 °C near 2–3 kbar and hardly varies in temperature up to 6 kbar; and the higher temperature transition increases from ≈ 872 °C (on heating) at 1 bar with slope ≈ 25 deg kbar⁻¹, to 5 kbar, with the hysteretic interval remaining essentially unchanged in the investigated range.