Vermont Gold. 361 



Al. Brongniart, Siderocriste, (Eisenglimmerscheiftr of Eschwege,) 

 and composed of quartz with the specular and magnetic oxides of 

 iron.* These are the two species of iron ore that occur at Hawley: 

 and it ought to be recollected, that in the vicinity of the iron mine in 

 that place, quartz predominates so much, that I have described the 

 rock as a variety of quartz rock. It is said, indeed, that the sidero- 

 criste is connected in Brazil with mica slate. But in the rock at Som- 

 erset mica occurs ; and I am by no means confident that some geolo- 

 gists would not regard it as mica slate ; and besides, the mica and 

 talcose slates are interstratified, and otherwise more intimately mixed; 

 so that I am disposed to believe that the formation which I have called 

 talcose slate, in Massachusetts and Vermont, corresponds to that con- 

 taining gold in Brazil, as nearly as could be expected in countries so 

 remote. And although at Somerset the gold has been found chiefly 

 in the hydrate .of iron, yet it probably exists also in the magnetic ox- 

 ide, and not improbably in the micaceous oxide at Hawley. The fer- 

 ruginous breccia that covers the siderocriste in Brazil, and probably 

 contains platina and diamonds as well as gold, has not to my knowl- 

 edge been found in Vermont or Massachusetts : yet it may be found 

 still, as very few researches have been made on this subject. 



We ought to guard against the idea that all gold must occur in tal- 

 cose slate, because we know that some does ; and because the happy 

 suggestion of Mr. Eaton on this subject led to the discovery of that 

 at Somerset. For veins of quartz containing this metal traverse other 

 rocks in France, Peru, and Mexico. They occur in granite, gneiss, 

 mica slate, argillaceous slate, and talcose slate, t Hence we may find 

 it in all these rocks, which are so intimately associated in Massachu- 

 setts and Vermont. 



Another interesting ore in the talcose slate of the Hoosac Moun- 

 tain range, is manganese. Tt exists in beds or interstratified layers 

 in the slate, precisely like the ores of iron above described. These 

 beds are found in Plainfield, and several of them occur near one an- 

 other, at two principal places, which are represented on the map: that 

 is, we find smaller and larger beds within a few feet or rods of one 

 another. These beds are rarely more than three or four feet thick. 

 Their surface is black or dark gray, apparently the common peroxide 



* See Tableau des Terrains, &c. p. 329 : Classification des Roches, p. 83 : and 

 Dictionnaire D'Historie Naturelle, Art. Or. 

 tDictionnaire D'Historie Naturelle, Art. Or. 

 46 



