Geology. a pebble or cobble that has been faceted, grooved, and polished by the erosive action of wind-driven sand.
The surface was a fine trash of ventifacts --stones that had been polished into smooth facets by blowing grit ...
Sarah Andrews, In Cold Pursuit, 2007
A little world, and completely filled with small black boulders, like fossil balls from various sports, only all black, and all faceted to one extent or another. They were ventifacts.
Kim Stanley Robinson, Green Mars, 1994
Ventifact, “stone shaped by the wind or sandstorms,” is a rare word, used in geology and physical geography, and is modeled on the much earlier noun artifact (artefact), which dates from the mid-17th century. Ventifact derives straightforwardly from Latin ventum “wind” ( venti- is the Latin combining form) and factum, the past participle, also used as a noun, of the verb facere “to make, do” (with as many senses as the English verbs). Latin ventum is related to English wind, winnow, and weather. Latin facere and the adjective facilis “easy, easy to do” derive from a very common Proto-Indo-European root dhē- “to put, place, set,” from which Germanic (English) derives do and deed, Greek tithénai “to set, put,” and Slavic (Polish) dzieje “history” (i.e., things done, deeds). Ventifact entered English in the early 20th century.