STRUCTURE OF METEORITES MERRILL. 179 



the hardness and shape of the diamond. In 1889 E. Weinschenk 

 separated from the Magura iron a minute quantity of transparent 

 crystals which were hard enough to scratch ruby, and burned in 

 oxygen, forming carbonic acid. In 1891 A. E. Foote, in cutting the 

 Canyon Diablo meteoric iron, found a black, vitreous mineral having 

 a hardness above that of sapphire, and which he announced to be 

 diamond. Later, O. W. Huntington, by dissolving a considerable 

 quantity of this iron, was able to isolate a considerable number of 

 minute, colorless particles which had not merely the hardness of 

 diamonds, but the crystal outlines as well. The crystals found by 

 Huntington were, it should be stated, minute — but about a hundredth 

 of an inch in diameter. Since Huntington's work, diamonds have 

 been separated from the Canyon Diablo and other irons by several 

 workers. 



Under the name of Cliftonite, Fletcher ki 1887 described a form of 

 carbon occurring in minute cubical crystals with dodecahedral and 

 tetra-kis-hexahedral modifications which he found in the iron 

 meteorite of Youndegin, West Australia. The crystals were of pure 

 carbon, easily frangible, with a hardness of 2.5 and specific gravity 

 of 2.12. After a full consideration of their crystalline form and 

 physical condition with especial reference to their possible pseudo- 

 morphous nature, Fletcher concluded that they represented "an allo- 

 tropic condition of crystallized carbon distinct from both diamond 

 and graphite," and gave the name, as above. 



Carbon in the form of graphite, both crystalline and amorphous, 

 is a common constituent of meteorites, particularly the iron-rich 

 varieties, where it occurs in disseminated scales and nodular masses 

 often of considerable size. The percentage amount by weight is al- 

 ways small owing to the relative lightness of the carbon, but in the 

 Novo-Urei, Orvinio, and some other stones, it is sufficiently abundant 

 to impart to them a decided dark gray to nearly black color. The 

 Novo-Urei stone was estimated to contain some 1.26 per cent of 

 amorphous carbon, and 1 per cent in the form of diamond. 



Cohenite is the name given to a carbide containing some 90 per 

 cent of iron, 3.5 per cent of nickel and cobalt, and 6.5 per cent of 

 carbon. Daubreelite is a sulphide of iron and chromite of the 

 formula, FeS, CrS 3 , which was isolated, analyzed, and named by 

 J. Lawrence Smith in 1876. Lawrencite is a green, semisolid ferrous 

 chloride almost invariably present in meteorites, but which undergoes 

 such ready oxidation as to shortly disappear on the immediate sur- 

 face. The mineral is a sore trial to all keepers of meteorite collec- 

 tions. Oldhamite is the name given by Maskelyne in 1862 to a cal- 

 cium sulphide found in the meteorite of Busti, India. It occurs 

 in microscopic proportions in rounded granular forms of a chestnut 

 brown color. Under atmospheric influences it passes by oxidation 

 into gypsum. The same investigator gave the name "osbornite" to 



