It crystallizes in the form of fibrous aggregates, masses, and vertically striated prismatic crystals. Large crystals are dark blue, often prismatic. Also, the use of these prismatic beam expanders led to the multiple-prism dispersion theory. These properties are due to fine grained non-aligned crystals with platy or prismatic habits. The arsenic ions are not octahedrally coordinated but have a trigonal prismatic coordination polyhedron. Notable examples include the trigonal prismatic W(CH) and octahedral W(CO). The body is cylindrical in its upper portion, and more prismatic below. However, strong eyeglass prescriptions create distortions such as prismatic movement and chromatic aberration. Its sides are embedded with prismatic blades traditionally made from obsidian. The tall base corners were originally designed to gently slope upward, and have prismatic glass. They can be telescopic in nature or prismatic. Another with prismatic glasses is the KMQ viewer. Ethnohistoric sources recount the process of prismatic blade production. Core configurations are being considered based on pin- or plate-based fuel assemblies or prismatic blocks. Often "prismatic" or "diamond" rustication is imitated.