poikilitic


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Related to poikilitic: ophitic, trachytic, poikiloblastic

poikilitic

[‚pȯi·kə′lid·ik]
(petrology)
Of the texture of an igneous rock, having small crystals of one mineral randomly scattered without common orientation in larger crystals of another mineral.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
At Burnt Point, massive, pegmatitic gabbro contains cumulus ortho- and clinopyroxene, and large poikilitic post-cumulus amphibole and plagioclase.
The main structure contains disseminated sulphides at the southern margin grading into net textured semi-massive and poikilitic massive ore in the core and northern edge of the bodies (up to 80% sulphides -- Figure 3).
The primary ore textures comprise euhedral-anhedral-grained, metasomatic, edge-shared, void-filling, poikilitic, slaty cleavage, skeletal, exsolution, graphic, crumpled, and cataclastic textures (Figure 4).
The Talavera sample shows large anhedral poikilitic orthopyroxene crystals, leading to a hypidiomorphic subophitic to ophitic texture.
In some thin sections the hornblende is poikilitic and contains inclusions of quartz.
3) Quartz occurs as cloudy anhedral grains with characteristic weak birefringence, prominent undulose extinction and low relief while muscovite occurs as tiny elongate plates with poikilitic crystals of quartz.
Occurrence: As a monomineralic veinlet cross-cutting poikilitic nepheline syenite.
5a), locally reaching 20 cm, and they sometimes have ragged poikilitic margins containing uniformly distributed inclusions of matrix minerals.
Finally, there are some rare but interesting boulders consisting of coarse-grained diorite with poikilitic megacrysts of amphibole that grew around leucocratic droplets (Fig.