Definition of vug in US English:



  • A cavity in rock, lined with mineral crystals.

    • ‘Cavities or vugs in the centre of the veins make it possible for minerals to grow into free space forming large and well-formed crystals.’
    • ‘It occurred as a fine-grained siliceous vein filling and as discrete, clear, tiny crystals in vugs.’
    • ‘The banded quartz is fascinating to study; euhedral crystals originally deposited in vugs and cavities were repeatedly covered with thin bands of agate.’
    • ‘Veins in some septaria do not fill the fractures completely but form elongated vugs that are sometimes lined with well-formed crystals.’
    • ‘Very narrow vugs containing quartz crystals are encountered in the quartz seams at times, but these invariably are barren of gold.’
    space, chamber, hollow, hole, pocket, pouch
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Early 19th century: from Cornish vooga.