so Mr. William Phillips's Description 



observable in the larger crystals. They are generally of a consider- 

 able external lustre, occasionally approaching to metallic ; and are 

 sometimes, though rarely, iridescent on the surface. In some of the 

 most recent specimens afforded by Huel Gorland, the crystals exhibit 

 •a singular external brilliancy, occasioned, apparently, by a deposition, 

 after the formation of the crystal, of small thin facets which 

 cannot be detached by the knife, of the same form as the faces of 

 the crystal itself. The crystals of this substance are mostly aggre- 

 gated, and frequently confusedly grouped : it is by no means common 

 to find one in which all the solid angles are disengaged. A singular 

 variety was found in small quantities in Huel Jewell mine, of a dark 

 . red colour and remarkable lustre, in hollow octohedrons, formed by 

 very minute crystals, each arranged in the same direction, and 

 attached at the solid angle. This variety is sometimes accompanied 

 by uranium in small tabular crystals of a light green colour. 



The compact red oxyd of copper, usually denominated tile ore, 

 Avhich by Brongniart is called Cuivre oxidule ferrifere, has been 

 'found in several mines in Cornwall. In Huel Gorland, this red oxyd 

 often occurred massive, sometimes with portions of native copper 

 .'passing through it ; and -in this state, as well as when crystallized, 

 passing into black oxyd. Crystals were frequently found deposited 

 on native copper, the irregular crystallizations of which formed, as it 

 were, the nuclei of the superimposed crystals ; and these were gene- 

 rally varieties, the primitive form being rarely found so circumstanced. 

 Crystals also occasionally enclose minute portions of native copper. 



Specimens of this substance occur, consisting almost wholly of a 

 • ptire mass of aggregated crystals ; it is however usually accompanied 

 ' by quartz, and occasionally by a compact and very hard substance, 

 apparently composed 6f quartz, in intimate fnixture^th the Gossan 

 •before described. It has also been found with fluor spar in Huel 



