Genth,] <jJu lAugustls, 



of mottled black serpentine of about 800 feet, and frequently imbedded in 

 the latter, masses of the same dark green serpentine. This immense bed 

 of serpontine, in its two varieties, rests upon chloritic slates, with numer- 

 ous crystals of magnetite in octahedra and twins, so called hemitropes, 

 aii,d talc slates, and below these again occurs another, but smaller bed of 

 green serpentine of about 180 feet in thickness, which like the other is 

 underlaid by chloritic and talcose slates, followed by a third bed of green 

 serpentine. 



A titaniferous variety of magnetite is found in lenticular masses of vari- 

 ous sizes, intercalated between the gi-een serpentine and is frequently 

 Ijounded on the hanging Avail by chloritic slates. 



The green serpentine is quarried for ornamental purposes as it admits of 

 a very fine polish and can be obtained in many beautiful shades of light 

 and dark green. 



The chloritic slate is genei-ally of a very fine scaly structure, sometimes 

 the scales become larger, from 0.5 to 1'"'" in diameter on an average, 

 but rareljr reaching 3™"'. 



At one locality in this large belt, a coarse scaly chlorite, immediately in 

 contact with talc slate, has disseminated through it numerous small octa- 

 hedra of talc, pseudomorphous after magnetite, an altei'ation, which, if I 

 am correct, has never been observed before. These crystals from 1 to 2""" 

 in diameter are of a silvery-white color and pearly lustre, the scales are 

 arranged parallel to the octahedral planes, in the center is occasional]}* a 

 small nucleus of magnetite, sometimes associated with pulvenilent 

 limonite. 



This alteration of magnetite crystals into talc is of importancg in connec- 

 uon with the steatite bed of 12 to 15 feet in thickness, to which I have 

 above referred, because it shows that no good reason can be given to con- 

 tradict the proi)osition that an entire magnetite bed has disappeared and 

 lias been replaced by steatite. This opinion is proved by the following 

 observations. 



The steatite is of a white or greenish-white color, it has mostly an un- 

 even fracture, some seams in it, however, graduate into a slaty structure. 

 Cryptocrystalline, and showing, wlien powdered, to be composed of an 

 aggregate of exceedingly fine scales. Disseminated through t7ie whole mass 

 are dark spots, from 0.1 to lO"^'^ in diameter. Especially the larger ones 

 sometimes have a definite shape of sq^lares or rJiomhs, or other forms, rep- 

 resenting sections of magnetite crystals. These dark spots of a dark gray 

 or iron-black color, are quite soft and can be reduced to a powder hy the 

 nail of a finger, and consist of fine scaly talc, "olored by remnants of tJie 

 original magnetite, which frequently can be separated by a magnet, or 

 dissolved out by hydrochloric acid. That only a small number of the 

 dark spots show the form of sections of magnetite, whilst most of them 

 are without definite shape, shows that tlie original magnetite in the bed 

 was granular or compact, but had, as is very common, crystals of magne- 

 tite disseminated through the whole mass. 



