138 



Mr. D. Forbes's Researches on the 



Chalcotrichite. 



Kermesite. 



Chalybdite. 



Lead (oxyiodochlo 



Chanaralite. 



ride). 



Chileite. 



Limonite. 



Chrysocolla. 



Libethenite. 



Cobalt bloom. 



Linarite. 



Eartby bloom. 



Malachite. 



Condurrite. 



Mimetene. 



Copiapite. 



Minium. 



Copperas. 



Olivinite. 



Copper (native). 



Pearlspar. 



Coquimbite. 



Pelokonite. 



Covelline. 



Pharmacolite. 



Cuprite. 



Psilomelane. 



Descloizite. 



Quartz. 



Dolomite. 



Stypticite. 



Embolites. 



Sulphur. 



Erinite. 



Tagilite. 



Erythrme . 



Vanadinite. 



Fibroferrite. 



Vanadiate of lead 



Gothite. 



and copper. 



Gypsum. 



Wad. 



Iodyrite. 



Wulfenite. 



Kerargyrite. 



Zincblende. 



Adamite. 

 Manganese alum. 

 Alumina (cupreous 

 silicophosphate) . 

 Alunogen. 

 Ammiolite. 

 Anglesite. 

 Annabergite. 

 Apatite (cupreous). 

 Arragonite. 

 Arsenolite. 

 Arseniate of nickel 



and cobalt (tribasic) 

 Arseniate of nickel 



(hydrous bibasic). 

 Asbolan. 

 Atacamite. 

 Azurite. 

 Bieberite. 

 Blakeite. 

 Brochantite. 

 Bromyrite. 

 Calamine. 

 Cerusite. 



(7) Minerals pertaining to the great Porphyrite Eruptions of the 

 Oolitic Period, with their inter stratified tuffs and other contem- 

 poraneous beds. 



These porphyries are seen both in the form of dykes break- 

 ing through the strata, and as immense beds of crystalline rock 

 interstratified with ashes, tuffs, and breccias, the two latter of 

 which apparently have been poured out under and more or less 

 broken up and stratified by the action of the ocean. These 

 rocks are true porphyries, being composed of crystals of felspar 

 in a felspathic base ; when occasionally some crystals of Uralite 

 are found in them, they become true Uralite porphyries ; but 

 quartz is never met with as a constituent, except in such circum- 

 stances as indicate that it has been produced as the result of 

 subsequent alteration, or of more or less complete decomposition 

 of the felspar in the rock itself. 



It is to be regretted that as yet no study of the felspar species 

 constituting these rocks has been made ; but triclinic felspars are 

 present, whilst oligoclase is noted as having been met with along 

 with soda-lime felspars. Thin beds of impure limestone and lig- 

 nite are occasionally met with amongst the stratified tuffs; and 

 in some of the porphyries the following zeolites have been spa- 

 ringly encountered : — Chabazite, Laumonite, Prehnite, scolezite, 

 and stilbite, as well as agate, common opal, and calcite, the latter 

 three minerals evidently formed from the decomposition of lime- 

 felspar. 



