Source: wikibot/circumscribed-halo
= Circumscribed halo
{wiki=Circumscribed_halo}
A circumscribed halo, often referred to in the context of geology and mineralogy, describes a specific type of alteration zone that surrounds a mineral deposit or a particular rock formation. In this context, the term "halo" indicates a zone around a central feature where certain characteristics, such as mineral composition or chemical properties, change due to processes like hydrothermal alteration or contact metamorphism.