An important aspect of the MEDE program consists of determining the energy dissipative mechanisms at the atomic and microstructure scales that together contribute to the deformation, damage, and failure of materials in extreme dynamic environments. The processing related and/or impact formation of atomic scale intragranular planar features may significantly contribute to energy dissipation mechanisms. Most of these features in the past have been identified as “twins”, which may not be correct in all cases. There are two general categories of planar features in boron carbide: processing related compositionally modified lamellar Wadsley-type defects and the formation of planar deformation features (PDFs) in a high stress event, the most common of which is nano-amorphization. Prior to the advent of High Resolution TEM many two-component phase equilibrium diagrams erroneously identified certain parts of the diagram as solid solutions but were an intimate mixture of nano-crystalline phases. A 1950’s B-C phase diagram, suggested that the boron carbide “solid solution” may actually be mixtures of B12C3 and B13C2 phases. Examples of Wadsley planar features in feldspar “solid solutions” will be presented. Amorphous planar deformation features (sometimes referred to as “Diaplectic” glass) in minerals (mostly quartz) have been known for some time and has been used to identify meteor craters. The still apparently unresolved question is if the glass is the result of a quenched liquid or a solid-solid transformation. Theoretical calculations of 3D crystallographic elasticity surfaces by Qinglei Zeng using the Taylor et al (2012) elastic constants show a significant increase in elastic anisotropy at elevated pressures which could lead to shear softening and localization forming shear bands and/or solid amorphization or melting and quenching to a glass, triggered by a violation of the Born stability criteria.