intrusiva

Intrusiva is the feminine form of the Italian adjective intrusivo, meaning intrusive or something that invades or intrudes. The term comes from Latin intrudere and is used in various fields to indicate intrusion or unwanted incursion. The masculine form is intrusivo and the plural intrusivi.

In geology, roccia intrusiva refers to igneous rocks formed when magma crystallizes below the Earth's surface. Slow cooling produces a coarse-grained texture, revealing visible crystals (phaneritic). These rocks contrast with extrusive (or effusive) rocks, which erupt onto the surface and typically have fine-grained or glassy textures. Common examples of intrusive rocks include granite, diorite, granodiorite, diabase, and gabbro. Plutonic bodies such as stocks and batholiths are large-scale manifestations of intrusive activity.

In other contexts, intrusiva can describe behavior, thoughts, or processes perceived as invasive or disruptive. For example, phrases like comportamento intrusivo (intrusive behavior) or pensieri intrusivi (intrusive thoughts) are used in everyday language and psychology to denote unwanted or inappropriate intrusion.

Usage and scope vary by discipline and language, but the core sense remains the same: something that intrudes or interrupts a space, process, or boundary, whether in the physical world (geology) or in social, cognitive, or observational contexts. See also intruso, intrusione, intrusivo, roccia intrusiva.