Pilastrite

Pilastrite is a term that has been used to describe a type of sedimentary rock. While not a formally recognized or widely used geological term in mainstream mineralogy or petrology, it appears in some older or specialized literature. The name itself suggests a connection to "pilaster," which can refer to a flattened architectural column or a projecting architectural element. In a geological context, this might allude to the rock's appearance or formation.

Descriptions of pilastrite, where found, often characterize it as a granular or conglomeratic rock. It might contain rounded or sub-angular fragments of various sizes cemented together by a matrix. The composition of the fragments and the matrix would vary depending on the source and depositional environment. Some references suggest that pilastrite could be a type of breccia or conglomerate with specific visual characteristics that led to its naming.

The lack of widespread adoption of the term pilastrite means that its precise definition, formation mechanisms, and geological significance are not clearly established within current scientific consensus. Geologists typically classify rocks based on more standardized nomenclature that describes mineral composition, texture, and origin, such as conglomerate, breccia, sandstone, or arkose. Therefore, encountering the term pilastrite would likely require further investigation into the specific context in which it is used to understand the intended rock type.