euhedral


Also found in: Wikipedia.

euhedral

[yü′hē·drəl]
(petrology)
References in periodicals archive ?
Elsewhere in Virginia, the high silica sandstone formation, referred to as the Oriskany Sandstone, has been described by Scholle (1979) as having quartz grains that are well rounded and show no euhedral overgrowths; however, they have irregular line contacts with adjacent minerals, and many quartz grains have strain shadows and Boehm lamellae suggesting significant deformation that would compromise their capacity to withstand high crush pressures (Scholie, 1979).
The coarse fraction of the samples was composed of euhedral and subhedral angular grains, mainly quartz, feldspars and plagioclases, with a small proportion of shards of acid volcanic glass, phytoliths, and mica and pyroxene grains.
The plagioclases are euhedral to subhedral that show evidences of fracture and breakage.
The dominance of finely disseminated microcrystalline euhedral K-feldspar and quartz in argillite suggests that these minerals in GA are commonly authigenic in origin.
Stockwork texture was detected due to filling of the network of altered ophiolite by subhedral to euhedral calcite crystals.
Euhedral to subhedral zoned oligoclase to andesine plagioclase (30% to 40%) and anhedral quartz (20% to 30%), in small pods, are the primary constituents of the rock.
2002) observed euhedral, prismatic gypsum crystals up to 1 mm long in the roots of nursery-grown pine seedlings, and attributed their formation to substrate dryness and excessive S supply through fertilisation, causing precipitation of gypsum in the root channel.
Zones of massive sulfide are typically surrounded by haloes of disseminated pyrite consisting of medium- to coarse-grained (1 to 4 mm) subhedral to euhedral pyrite grains that make up 5 to 20% of the rock.
The area that hosts the source of Mbwemkuru River and its tributaries is elevated to about 700m above sea level and contains gravels that are euhedral to sub angular shapes.
50-55]) forms subhedral to euhedral, homogeneous, in places weakly zoned grains often containing inclusions of titanomagnetite.