| They found that the most prevalent defect was formation of a new triclinic polytype, with an ionic arrangement closely related to that in the accepted structure. |
| They are triclinic, with cleavages meeting at approximately 86 degrees. |
| These are, in order of decreasing symmetry, the cubic, hexagonal, tetragonal, trigonal, orthorhombic, monoclinic, and triclinic systems. |
| We then indexed the remaining K-feldspar peaks assuming a triclinic unit cell according to Appendix A11 of Ribbe. |
| The K-feldspar has local development of mottled texture due to variable inversion to triclinic microcline, and quartz has rare subgrain development. |
| All the sodium, sodium-calcium, and calcium species are triclinic, except the rare monoclinic sodium felspar barbierite. |
