COLOPHONITE. 



Analysis, from Ezquerra, by Berthier : 



Alumina .... 44*5 



Silica 15-0 



Water 40-5 



100-0 



BB infusible. In water becomes trans- 

 parent, and crumbles to pieces : dissolves in 

 acids, and the solution yields a ^elly on 

 evaporation. 



Localities. Near Schemnitz in Hungary, 

 and Wissenfels in Saxony, in porphyry. 

 Ezquerra in the Pyrenees. 



Name. From x'>^>^'i^ gl^^s; from its gela- 

 tinous appearance. 



Brit. Mus., Case 26. 



CoLOPHONiTE. The varieties of iron- 

 lime Garnet which have a resinous lustre. 

 S.G. 3-896. 



Fig. 124. 



Localities. Arendal in Norway. United 

 States ; in New York, at Roger's Eock ; 

 and at Willsboro', Essex co., forming a 

 large vein in gneiss, associated with Tabular 

 Spar and green Coccolite : also at Lewis. 



Name. From Ko'Ao(fuv, a city of Ionia 

 whence resin was obtained ; in allusion to 

 the resinous aspect of the mineral. 



JBrit. Mus., Case 36. 



CoLUBRiNE, French. See Potstone. 



CoLUMBATE OF Irox. See Tantalite. 



CoLUMBiTE, Hatchett. Rhombic: it oc- 

 curs in single crystals and in small crystal- 

 line masses; the crystals are mostly incom- 

 plete, but possess the general form of right 

 rhom.bic prisms, striated longitudinalh% 

 with the lateral edges truncated, and vari- 

 ously modified. Colour greyish or brownish- 

 blaclc, often iridescent, with a dark brovv-n 

 streak. Opaque with metallic lustre. 

 Scratches glass, and gives sj)arks with 

 steel. Brittle. Fracture sub-conchoidal, 

 and imperfectly laminar. H. 6. S.G. 5-4 

 to 6-4. 



Fig. 12a 



COMBUSTIBLE COPPER ORE. 91 

 Analysis, from Evigtok : 



Columbic acid (Niobic acid) 78'74 

 Protoxide of iron . . . 16-40 

 Protoxide of manganese . 5*12 

 Oxide of tin and tuugstic acid 0-16 



Covip. Columbate of protoxide of iron 

 and of manganese or (Fe, Mn) -O-'b^. 



100-42 

 This analysis is almost identical with those 

 of specimens from Middlelown, U.S., by H, 

 Rose. 



BB alone, on charcoal, infusible ; but it 

 becomes somewhat rounded at the corners :, 

 dissolves slowly in borax, to which it im- 

 parts a blackish-green colour. 



Localities. The finest crystals have been 

 found in a felspar-quarry at Middletown ; 

 one of them, described by Professor Johnston, 

 Aveighed ] 4 lbs., another 6| lbs. It has also 

 been met with at Chesterfield and Beverly 

 in Massachusetts, in granite ; and at Had- 

 dam in Connecticut, where it was first dis- 

 covered, it occurs in a granite-vein, v.ith 

 Beryl, Chr\-soberyl and Automolite. The 

 Columbite of Bodenmais in Bavaria is also 

 found in granite associated with Beryl. 

 The most beautiful variety of this mineral 

 hitherto procured, remarkable for its well - 

 developed and highly-modified crystalliza- 

 tion, is that from Evigtok, in the fiord of 

 Arksut in Greenland. At first it appears to 

 resemble certain kinds of Tinstone, the crys- 

 tals being either loose or enveloping pieces 

 of decomposed Felspar, or covering the sides 

 of small cavities in the latter mineral. It 

 does not exhibit the beautiful iridescence of 

 the American Columbite. 



Name. The name Columbite was be- 

 stowed on this mineral from its having beea 

 first discovered in America. 

 Brit. Mus., Case 38. 



Columnar Heavy Spar. This mineral 

 (which is the Stangenspath of Werner) oc- 

 curs crystallized in yellowish, milk-, grej'ish- 

 and greenish-white, acicular, oblique rhom- 

 bic prisms, which are generally ill-defined 

 and aggregated laterally into columns, and 

 intersect one another. It has a shining 

 pearly lustre, is translucent, and easily 

 frangible — breaking with a straight foliated 

 fracture. It is found in metallic veins at 

 Freiberg in Saxony. It may be distin- 

 guished from white -lead ore (Cerusite), to 

 which it bears a resemblance, by its pearly 

 lustre, foliated fracture and specific gravity, 

 which is not above 4-5, while that of white- 

 lead ore is 6-55, its small conchoidal frac- 

 ture, and its lustre adamantine. 



Combustible Copper Ore, Kirwan. 

 Bituminous Shale or Coal impregnated with 

 Copper, 



