groundmass

noun
ground·​mass | \ ˈgrau̇n(d)-ˌmas How to pronounce groundmass (audio) \

Definition of groundmass

: the fine-grained or glassy base of a porphyry in which the larger distinct crystals are embedded

First Known Use of groundmass

1879, in the meaning defined above

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The first known use of groundmass was in 1879

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Cite this Entry

“Groundmass.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/groundmass. Accessed 12 Aug. 2020.

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Britannica.com: Encyclopedia article about groundmass

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