FOLIATED COPPER. 



on the angles or edges. This property is 

 destroyed by exposure to a red heat. ' In 

 all other respects this variety resembles com- 

 mon Quartz. It is found near Nantes in 

 France, and in various parts of the United 

 States. 



FoLiATKP Akseniate OF CopPER. Cleave- 

 land. See Chalcophyllite. 



Foliated Black Manganese Ore, 

 Jameson. See Hausmannite, 



Foliated Tellurium, Allan. See 

 Kagyagite. 



Foliated Zeolite, Jameson^ Werner. 

 See Heulandite. 



Foliated Zeolite, Jameson. See Fo- 

 liated Stilbite. 



FoNTAiNEBLEAU LiMESTONE. Aggre- 

 gations of secondary rhombohedrons of 

 Calcite, which contain a large amount of 

 sand, mechanically mixed with them. The 

 similar variety of Calcite which occurs in 

 great quantities in the sands on the African 

 coast, between Sandanha Bay and Ichaboe 

 Island contain as much as 15 or 20 per 

 cent, of sand. 



FoRSTERiTE, Levy. A variety of Chryso- 

 lite, occurring in small, brilliant, white or 

 colourless, translucent crystals at Vesu- 

 vius, where it is associated with Pleonaste 

 and olive-green Pyroxene. H. about 7. 



Fig. 198. 



Fossil Copal, Phillips. Pee Copaline. 

 Fossil Lightning. See Fulgurite. 

 Fossil Oil, Jameson. See Naphtha and 

 Petroleum. 



Fowlerite. The variety of Rhodonite 

 which occurs in large crystals, with Frank- 

 linite, at the Franklin Furnace, at Stirling, 

 in New Jerse}'. It is often black externally 

 from alteration, the action of the air con- 

 verting the protoxide of manganese into 

 }ieroxide. 



Analysis, by W. Camac : 



Silica . . . . .42-20 

 Protoxide of manganese . 25 -37 

 Protoxide of iron . . .11-00 

 Oxide of zinc . , . 4-15 



Lime 966 



Magnesia . . . .5-27 

 Felspar .... 3-56 



101-20 



Name. After Mr. S. Fowler. 



FRANKLINITE. 143 



Brit. Mus., Case 26. 



Francolite, Henry. A variety of Apa- 

 tite, occurring in small compound crystal- 

 line masses. At Fowey Consols in Cornwall 

 it is met with in minute, wliite, and trans- 

 parent crystals, and in thin plates, asso- 

 ciated Avith Quartz and Chalcopyrite : also, 

 in thin hollow cubes above an inch square, 

 which, when discovered, are half filled with 

 a transparent fluid. The colours of the 

 specimens from Huel Franco, near Tavi- 

 stock, were greyish-green to brown. 



Comp. 8Ca P + Ca Fe = lime 49-48, phos- 

 phoric acid 41-34, calcium 3-96, fluorine 1-80, 

 chlorine 3-42=- 100. 



Mean of two analyses by Henry ; 

 Phosphoric acid . . . 41-57 



Lime 53-09 



Protoxide of iron and prot- 

 oxide of manganese . 3-09 

 Fluorine and loss . . . 2-25 

 Chlorine .... trace 



100 



Name. After that of the locality where it 

 was first discovered, Huel Franco. 



M. P. G. Horse-shoe Case, No. 313. 



Frankenburg Corn-ears, Nicol. See 

 CuiVRE Spiciforme. 



Franklinite. Cubical. Occurs in grains 

 or in granular masses, composed of imper- 

 fect_ crystals, occasionally exhibiting the 

 planes of the octahedron. The structure is 

 lamellar, parallel to the face of the regular 

 octahedron. Colour iron-black, with a me- 

 tallic lustre. Opaque. Brittle. Fracture 

 conchoidal. Acts slightly on the magnet. 



H. 6 to 6-5. S.G. 5. to5 3. 



Fig. 199. 



Comp. (Fe, Zn)3 (Fe, Mn)=iron 45-16, 

 manganese 9-38, zinc 20-30, oxygen 25-16, 

 = 100. 



Analysis (mean of three), by Rammels- 

 berg : 



Peroxide of iron . . . 64-51 

 Peroxide of manganese . 13-51 

 Oxide of zinc . . . 25-30 



103-52 

 BB infusible : with borax forms a green 

 glass, which, when completely saturated, 

 becomes red, and on cooling assumes a 



