MINERALOGY. ' 305 



arranged wifli reference to one another as are quartz and feldspar in 

 sclirift granite, and, as in tliis case tlie mineral intermingled with 

 the feldspar is hexagonal. In composition it is somewhat related 

 to muscovite or nepbelin. It is white and fibrous, and only detected 

 by microscoi)ic examination. ]S"amed from £3, well, and xpuTrrdg, con- 

 cealed. 



MtraUte. — A dark-green chloritic substance, resembling delessite, and 

 found by F. J. Wiik, at Eura Kirchspiel, Finland. 



Fairjieldife. — An hydrous manganese calcium phosphate, found by Brush 

 and Dana, at Branchville, in Fairfield County, Connecticut. It is a 

 colorless and transparent mineral with a good cleavage, and trichnic 

 in crystallization. 



Filloicitc. — A mineral found by Brush and Dana at Branchville, and 

 named after the owner of the property on whose land they explored. 

 Occurs in granular and crystalline grains, the latter looking like 

 rhombohedrons but really monoclinic in form. It is a manganese 

 phosphate containing a little iron and soda, and of a wax-yellow color. 



Fredriciie. — A mineral related to tetrahedrite, but contains lead and 

 tin. It is found in nuissive, iron-black pieces, at the Fain mine, 

 Sweden, and Is chieily composed of copper, sulphur, and arsenic. 

 Desciibed by ITj. Sjiigren. 



Gelatinous chahazite. — Renevier found a gelatinous substance in fissures 

 in the conglomerate near Lausanne, Switzerland, that had the com- 

 position of cliabazite. He called it a mineral in emluyonic condition. 

 This was inappropriate, because no such condition is possible in the 

 organic kingdom. A mineral is complete as soon as formed, and 

 its crystalline condition is one of its essential i)roperties. This is a 

 new mineral if its composition is definite. 



Guejarite. — A copper antimony sulphide, found by M. E. Cumenge in a 

 vein of spathic iron, at Guojar, in the Spanish Sierra IsTevadas. Oc- 

 curs in bright crystalline plates, that are sometimes quite large. It 

 is quite heavy, is steel-gray in color, and of rhombic crystallization. 



Hannayite. — A hydrous magnesium ammonium phosphate found in the 

 guauo beds at Victoria. It was determined and named by vom Eath, 

 and found to be triclinic in crystallization. 



Haufjhtonife. — A black mica, which was taken out of gneiss from Eoneval, 

 and analyzed by Ileddle. It is intermediate between biotiteand lepi- 

 domelane, and consequently scarcely needs any new name. 



Heldhm-giie. — Another mineral of unknown composition, but i^ossessing 

 angles like those of Zircon. It is a yellow mineral seen in the feldspar 

 of phonolite from Heldburg in Colbnrg, by O. Luedecke. 



Herrenfirundite. — A basic copper sulphate from Ilerrengruud, Hungary. 

 Occurs in six-sided tabular crystals of the monoclinic system. In 

 color it is dark emerald green. Occurs mixed with gyi)sum, malachite, 

 and calcite. .(See urvoJgyrite.) 

 S. Mis. 31 20 



