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Douglas Harper's Etymology Dictionary

1818, from Cornish vooga "a cavity in rock; cave, hollow."


n. A small to medium-sized cavity inside rock that may be formed through a variety of processes.


A vug, vugh, or vugg is a small to medium-sized cavity inside rock. It may be formed through a variety of processes. Most commonly, cracks and fissures opened by tectonic activity ( folding and faulting) are partially filled by quartz, calcite, and other secondary minerals. Open spaces within ancient collapse breccias are another important source of vugs. Vugs may also form when mineral crystals or fossils inside a rock matrix are later removed through erosion or dissolution processes, leaving behind irregular voids. The inner surfaces of such vugs are often coated with a crystal druse. Fine crystals are often found in vugs where the open space allows the free development of external crystal form. The term vug is not applied to veins and fissures that have become completely filled, but may be applied to any small cavities within such veins. Geodes are a common vug-formed rock, although that term is usually reserved for more rounded crystal-lined cavities in sedimentary rocks and ancient lavas.

The word vug was introduced to the English language by Cornish miners, from the days when Cornwall was a major supplier of tin. The Cornish word was vooga, which meant "cave".

Vug (disambiguation)

Vug is a cavity in a rock.

Vug may also refer to:

  • A Titanian individual in Philip K. Dick's science fiction novel The Game-Players of Titan
  • An acronym for Vivendi Universal Games.
  • Track 2 on side one of the album, Death Walks Behind You, by Atomic Rooster.
  • A monster that hides under the narrator's rug in the Dr. Seuss book There's a Wocket in My Pocket.

Usage examples of "vug".

Extending pseudopodia, the vug inspected the deed, then returned it to Luckman.

He held the door wide, and the two officers entered the apartment, the vug E.

The vug inside, cadging drinks, clipping Terran customers, rolling them in an educated way.

You thought that psychiatrist, Doctor Philipson, was a vug, and then you thought I was a vug.

And then he saw, past the vug, Carol Garden seated at the kitchen table, her face waxen.

We have been waiting a long time for you, a vug thought-propagated to him.

On the screen the image of a vug formed, and Joe Schilling reflected that it looked to him at leastlike any other vug.

A vug Peter Garden, a vug Joe Schilling, a vug Dave Mutreaux, and, slightly behind the others, a vug Mary Anne McClain.

The vug, in authentic shape, no longer requiring the artificial hull, was emerging.

Out of each discarded human husk a vug emerged, and the husks teetered and one by one, as if blown by an impalpable wind, writhed and then danced away, weightless, already without color.

Tendrils of gray smoke, cold and damp, sifted onto the Game-table and the vug shapes opposite them dimmed into an irregular obscurity.

Now the vug drew a card, examined it, and its piece moved ahead nine spaces.

The vug had now lost back over half of what it had won on its great previous move.

And, like Pretty Blue Fox, the vug could not conceal its dismay at a major setback.

He scrutinized the vug, as everyone else in Pretty Blue Fox was doing, trying to discover some indication.