1. Editorial

   EditorialNotes Pages: 295 - 296

2. Fugacities of gases and some mineralogical reactions at very high pressures and temperatures (an extrapolation)

   • I. A. Ostrovsky
   • B. N. Rizhenko

   OriginalPaper Pages: 297 - 303

3. High-temperature stress relaxation of synthetic, polycrystalline galena

   • Barry Kean Atkinson

   OriginalPaper Pages: 305 - 315

4. Vibrational structure of the S ₂ ⁻ luminescence in scapolite

   • R. P. Burgner
   • Barry E. Scheetz
   • William B. White

   OriginalPaper Pages: 317 - 324

5. A computer model for the cubic sodalite structure

   • D. Taylor
   • C. M. B. Henderson

   OriginalPaper Pages: 325 - 336

6. The thermal expansion of synthetic aluminosilicate-sodalites, M ₈(Al₆Si₆O₂₄)X ₂

   • C. M. B. Henderson
   • D. Taylor

   OriginalPaper Pages: 337 - 347

7. The effect of crystal field stabilization on the olivine→spinel transition in the system Mg₂SiO₄ - Fe₂SiO₄

   • Roger G. Burns
   • Chien-Min Sung

   OriginalPaper Pages: 349 - 364

8. Dynamics of dehydration in stilbite-type structures; stellerite phase B

   • A. Alberti
   • R. Rinaldi
   • G. Vezzalini

   OriginalPaper Pages: 365 - 375