E. MINERALOGY AND GEOLOGY. 245 



burg, N. J. It occurs in druses, lining the walls and cavi- 

 ties, and also in foliated aggregates of minute crystals. The 

 color is bluish black, lustre metallic, specific gravity 3.907. 

 Its composition is very remarkable, since it contains zinc 

 oxide, manganese monoxide and dioxide, and water. It is 

 therefore a hydrate of manganese and zinc, containing the 

 former metal in two states of oxidation. By heating it 

 changes color, and becomes of a tint varying from yellowish 

 bronze to copper red. The new mineral is apparently a 

 product of the decomposition of franklinite and some of its 

 associated species. 



THE MASSACHUSETTS SILYER-LEAD MIXES. 



The following facts concerning the development of silver- 

 mining in Massachusetts are given on the authority of Mr. 

 C. W. Kempton, mining engineer, of Newburyport, Massa- 

 chusetts. The mining region, according to the statement of 

 this gentleman, extends from Gloucester, Massachusetts, on 

 the south, to Portsmouth, New Hampshire, on the north, 

 and from the Atlantic, on the east, to a line drawn north and 

 south through "Great Pond," North Andover, Massachu- 

 setts, on the w r est. Within this region is located the first 

 discovered, and thus far the most prominent lode the 

 "Chipman" situated in the northerly part of Newbury- 

 port, and which has been traced for a distance of three miles. 

 The dip is nearly vertical, and slightly to the north. The 

 ore is chiefly galena, carrying from 50 to 150 ozs. of silver 

 to the ton, with some gold, blende, copper, and pyrites. 

 There is native silver in the quartz, and stephanite has been 

 found. The Chipman and Boynton shafts are on this lode ; 

 the last named is down, at the time of this writing, some 100 

 feet. About $20,000 worth of galena ore was taken out of 

 the Chipman at the start, in sinking the first 75 feet of the 

 shaft. The average thickness of vein-rock on the Chipman 

 lode is about 60 feet. The lode lies between granite on the 

 north and slate on the south. There are not less than eleven 

 parallel veins in this section of the mining district, on sev- 

 eral of which mining operations have been commenced, 

 showing well in the majority of cases. 



Our informant likewise notices a second variety of ore, 

 viz., the veins carrying tetrahedrite, which often runs ex- 



