crosta

Crosta is an Italian term meaning crust or rind and is used in several different scientific and everyday senses. In general, the word denotes an outer, hardened, or protective layer that forms on a surface or object.

Geology and planetary science

In geology and planetary science, crosta refers to the outermost solid layer of a planetary body: its crust. Earth has continental crust, which is thicker and less dense, and oceanic crust, which is thinner and more mafic. Continental crust typically ranges from about 25 to 70 kilometers in thickness, while oceanic crust is roughly 5 to 10 kilometers thick. The crust rests on the mantle and is broken into tectonic plates whose interactions drive earthquakes, volcanism, and mountain-building. The term is also used in discussing the crusts of the Moon, Mars, and other rocky bodies.

Food and culinary use

In everyday language, crosta describes the crust of bread, pastries, or baked foods—the browned, often crisp outer layer formed during baking. The crust contributes aroma, texture, and flavor and contrasts with the softer interior, or crumb, of the product.

Medicine and dermatology

In medical contexts, particularly in Romance-language usage, crosta denotes a scab or crust on the skin formed from dried serum, blood, or exudate as part of healing. A crosta typically forms over a wound or lesion and gradually detaches as the skin regenerates.

Etymology and usage

Crosta derives from Latin crusta, via Italian, reflecting its core sense of a hardened outer layer. The term is most commonly encountered in Italian language contexts and in translated scientific writing.