...
Dominant typically blocky, highly angular transparent and clear, occasionally slightly yellowish quartz (volcanic or high-grade metamorphic provenance ?). Significant (~5%) component of fresh black glassy bubbly lava (resembling pumice), few wind-abraded grains with desert varnish; very few grains of chlorite/epidote minerals. Interesting incongruent composition. Traces of well rounded quartz grains and recent plant seeds
...
...
Texture:
Coarse-grained (cU, median ca. 1000µ); poorly sorted, angular.