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A dense, homogeneous rock with constituents so fine that they cannot be seen by the naked eye.

[From Greek aphanēs, unseen : a-, not; see a-1 + phainesthai, phan-, to appear, passive of phainein, to show; see phenomenon.]

aph′a·nit′ic (-nĭt′ĭk) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


of or resembling aphanite
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.aphanitic - of or relating to aphanite
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
The South Flow zone displays aphanitic texture, zones of quartz-carbonate fracture filling, 7-10% disseminated fine-grained whispy pyrite and associated with increased silica alteration.
The Cuarzomonzodiorites are considered as igneous rocks of aphanitic texture, rich in silicon oxides; they are is generally the mineralogical species with larger sizes.
Rock fragments bearing crystals smaller than 0.062 mm were recorded as "labile" (L) according to the criteria of Dickinson (1970), and were usually aphanitic fragments of phyllites, slates and schists.
(1) a 92.5-foot thick aphanitic layer of calcarenitic limestone, commonly marly and fossiliferous; (2) a 233-foot thick aphanitic limestone; and (3) a 110.5-foot thick layer of dolomite and shale, with angular granitic sand and fine conglomerate at the bottom.
examine the aphanitic buildup from the onset of the Mulde Event (Homerian, middle Silurian) at Whitman's Hill (UK) and thus open up discussion on the significance of microbial fabrics.
The project area is characterized by two main geological formations: aphanitic and porphyritic geological structures (Figure 12(a)).
Meanwhile, analyses of this type should be restricted to aphanitic (homogenous and fine-grained) materials.
For this type of rock mass, its surface rocks instantaneously generate tensile failure right with the beginning of excavation; then aphanitic microcracks start to develop throughout the columns along with the reduction of surface rock confining pressure and induce a secondary failure of original joints, which finally leads to a progressive failure pattern similar to "domino effect." Currently, studies on the unloading mechanical properties of columnar jointed rock mass appear to be quite limited.
Andesite is an aphanitic and extrusive igneous rock composed of the Na-rich plagioclase, pyroxene and amphibole.
Basaltic to andesitic rocks of the East Bay Hills Group are typically aphanitic and massive, with slight to moderate porphyritic textures.