oreform

oreform is a term used in geology to describe the characteristic shape or form that a mineral or mineral aggregate takes as it grows. This shape is influenced by the crystal structure of the mineral and the conditions under which it formed, such as temperature, pressure, and the availability of space. While often used interchangeably with crystal habit, orreform can sometimes refer to larger-scale textural features in rocks.

Common orereforms include massive, granular, fibrous, bladed, and prismatic. A massive orreform indicates a lack of discernible crystal faces, often occurring when a mineral crystallizes in a confined space or as an aggregate of many small, randomly oriented crystals. Granular orereforms are composed of interlocking grains, frequently seen in igneous and metamorphic rocks. Fibrous orereforms are characterized by long, thread-like crystals, which can be either parallel or radiating. Bladed orereforms are flattened and elongated, while prismatic orereforms are elongated in one direction with distinct crystal faces at the ends.

Understanding the orreform of a mineral can provide valuable clues about its formation environment and the geological processes that have affected it. For instance, rapid crystallization might lead to more distinct crystal shapes, whereas slow growth or interference from other growing crystals can result in more irregular or massive orereforms. The study of orereform is an important aspect of mineralogy and petrology, aiding in mineral identification and the interpretation of geological history.