G R E 



[207] 



G R Y 



Druidical temple at Stonehenge, are 

 composed of this siliceous sandstone. 

 "Boulders of druid sandstone," 

 observes Dr. Mantell, " also occur 

 in the shingle bed, and calcareous 

 deposit at Brighton, and may be 

 observed lying on the sea-shore in 

 considerable numbers, after a recent 

 fall of the cliff. Upon comparing 

 the sandstone of Stonehenge with 

 that of Sussex, no perceptible dif- 

 ference can be detected. 

 GKIT. The provincial term for a 

 coarse siliceous sandstone. Some 

 of the strata of this description 

 have been worked for mill- stones, 

 from which circumstance they have 

 been called mill-stone grit. The 

 mill-stone grit is an important 

 deposit in the north of England, 

 from the Coquet to the Tyne, and 

 on the hills between the dales of 

 Durham and York, from the Tyne 

 to the Kibble. 



GBO'SSTJLAB. (from groseille, Fr. a 

 gooseberry, thus named from its 

 gooseberry green colour.) A very 

 rare mineral. The asparagus green 

 variety of dodecahedral garnet. It 

 is found in Siberia. Its constit- 

 uents are, silica 40 '50, alumina 

 20-10, lime 33- 80, oxide of iron 

 5'00, oxide of manganese 0*50. 

 GBO'WAN. 1. A Cornish name for a 

 soil formed of disintegrated granite. 

 The growan occupies a very consid- 

 erable area of the peninsula of 

 Cornwall, constituting no less than 

 three hundred thousand acres. The 

 fertility of the growan soil varies 

 greatly, and is in proportion to the 

 amount of felspar in the subjacent 

 granite. The hard growan varies 

 extremely in its hardness, but in 

 respect to its composition, it is 

 perfectly like the soft growan. 

 Some of the hard growan after 

 being exposed for a few months to 

 the weather, has dissolved com- 

 pletely into a soft growan. The 

 soft growan is nowhere hard enough 

 to support itself. The hard growan 



is jointed in all directions. 

 2. Those veins that are called lodes 

 by the miners are divided into two 

 classes, those formed of granite 

 being called growan, and those of 

 porphyry elvan. 



GBUM. The name given by the 

 miners to a dull dark red and green 

 impure concretionary limestone, in 

 parts ferruginous, each geode being 

 enveloped in red shale. It occurs 

 in the coal measures, and sometimes 

 attains a thickness of twenty feet. 

 The productus hemisphsericus and 

 another species are most abundant 

 in it, together with the corals 

 Lithostrotion floriforme, Syringo- 

 pora reticulata, and Lithodendron 

 irregulare. Sir R. MurcMson. 



GBYPH^E'A. (fomgryps, Lat. a griffin.) 

 An inequivalved bivalve ; the low- 

 er valve concave, terminated by a 

 beak, and curving upwards and 

 inwards; the upper valve much 

 smaller, like an operculum; the 

 hinge toothless, the pit oblong and 

 arched: one impression in each 

 valve. From the curved beak of 

 the shell, Linnaeus placed it among 

 the anomise ; but Lamarck placed 

 it under a distinct genus. 



GBY'PHITE. ( gryphites, Lat.) A fos- 

 sil bivalve belonging to the ge- 

 nus gryphsea. This deeply-incur- 

 ved bivalve is so abundant in some 

 of the beds of lias in France, as to 

 have occasioned them to be called 

 Calcaire a gryphites. These shells 

 are known in this country by the 

 provincial name of " miller's 

 thumbs." 



GBY'PHITE GBIT. A local term as- 

 signed by Sir R. Murchison to a 

 stratum of the inferior oolite of 

 Gloucestershire : it is thus named 

 from the prevalence in it of the 

 Cryphasa Cymbium. 



GTTAYACAN'ITE. A newly discovered 

 mineral from the Cordilleras of 

 Chili, consisting of copper, arsenic, 

 and sulphur. Hardness 3*5 to 4. 

 Specific gravity 4'39. 



