1 882.] Mineralogy. 527 



pyrite, a large proportion should be considered as produced 

 by the alteration of magnetite. Nearly half the crystals ex- 

 amined were attractable by the magnet, and all possible grada- 

 tion between typical magnetite and hematite, both in magnetism 

 and composition, were observed. 



Smaltite from Colorado. — Smaltite 1 has been discovered in 

 Gunnison Co., Colorado, in sufficient quantities to lead to the 

 belief that it will be a commercial source for cobalt. It is as- 

 sociated with calcite, erythrite, and occasionally pyrite and 

 spongy leaflets of native silver. A sample from the surface gave 

 M..VV. lies the following result :— 



Co Fe As SiO, Pb S Bi Cu Ni Ag 

 11.59 11.99 63.82 2.60 2.05 1.55 1. 13 0.16 trace trace = 98.89 



New Mineral Resins.— Muckite. This is a resin found in 

 cretaceous lignite in Moravia, and named by Schr6ckinger. It 

 has the formula C 2) H, 8 2 . Neudorfite. This is a resin associated 

 with the above, and probably a mixture. 



The Sand of the Desert of Sahara.— A mineralogical study 

 of the sand of the desert of Sahara has brought out some partic- 

 ulars of interest. The sand is of a yellow color. The quartz 

 grains, which constitute ninety per cent, of the sand are remark- 

 ably rounded and not so angular as those of sea sand ; a fact evi- 

 dently due to attrition by the action of the wind. It is found that 

 more than nine per cent, of the sand is composed of grains of 

 felspar. Other minerals which exist in small proportions are 

 Chalk, clay, halite, sylvite, magnetite, chromite, garnet, olivine, 

 amphibole and pyroxene. 



Mini- 



Notes.— Bcauxite, a substance recently she 



°y Fischer to be a mixture, frequently contains considerable 

 quantities of titanium and van uiium. It has been concluded by 

 Uieulafait that bcauxite originates from the decay of primitive 

 grannie rocks, and that if so, these rocks should contain titanium 



piper in the C-mptes Rtndns, he 



Urates that this is tlrV ci-a\ and that these elements are widely 



diffused throughout th • old -r form itions. Certair 



taIs of/>/«W* possess, in addition to the six characteristic cleavages 

 of ordinary bleu le, three oth r planes of equallv ready cleavage, 



which have recentlv been sf.i lied bv 1 1 mtcfemlK Conante, 



or more properly, Comantr, has been shown by Bertrand to be 



Probably hexagonal. M \V. lies has detected a vanadium 



mineral, probably Declnnitc, forming red and yellow incrusta- 

 'ons ; ,t so;ne mines in L>akdlle. Col An analysis of the in- 

 crustation was as follows : SiO, $6.$6, PbO 38.5 1, ZnO 9.07, V 2 5 

 'l-c.jSo. 



