^jLiutrcLLs m Granite. 



507 



eter : but such crystals are irregular and devoid of beauty. In Wil- 

 liamsburgh they sometimes occur smaller, but more valuable. F rom 

 Pelham I have a specimen of a greenish yellow bt ry], of considera- 

 ble beauty : they are said also to have been foun d in Worthington : 

 and Dr. Marshall showed me a fine crystal 1 1-2 inch diameter, found 

 in the granite of Fitchburg. In Stow, also, this mineral has been 

 found in granite. 



It has been stated that ioliteis found in the granite of Goshen : but 

 I have never met with it. 



Garnet is less abundant in our granite than in several of the older 

 stratified rocks. Generally v\here it does occur, it is in quite small 

 crystals ; but it is commonly the precious garnet. In Bedford it is 

 said to be found in large and sometimes perfect t rapezoidal crystals. 



If No. 1529. do not belong to the zeolite family of minerals, I 

 cannot tell where to refer it. I mean the radiated mineral upon fine 

 granite from Goshen. 



I believe that all the veins marked on the geological map, as well 

 as on Plate XVII, as lead veins, in Hampshire County and the south 

 part of Franklin, are either entirely contained in granite, or pass 

 from that rock into mica slate. Hence the minerals which they con- 

 tain may properly be described in this place. 



The gangue of the most southerly vein in Leverett is sulphate of 

 baryta and quartz. It is only a foot or two in width, and is entirely 

 in granite. It contains galena only. The most northerly vein in 

 that town is several feet wide, and is mostly in mica slate. It 

 contains galena and pyritous copper in nearly equal proportion. 



The vein in Southampton, to which I have often referred, and which 

 has been explored farther than any other in the State, traverses gran- 

 ite and mica slate ; and the gangue is mostly quartz with sulphate of 

 baryta occasionally. Its extent and situation have, however, been al- 

 ready given in the first part of my report with sufficient minuteness. 

 Galena is the principal ore. Blende, however, is frequent, as well as 

 pyritous copper. Here also have been found the carbonate, molybdate, 

 sulphate, phosphate, and murio- carbonate of lead ; the blue and 

 green carbonate of copper and vitreous black oxide of iron. Here 

 also we find sulphuret of iron in small oxtahedra, truncated on all 

 their angles. The carbonate of lead is found in tabular prisms 

 with bevelments : also in six sided prisms with four sided acumin- 

 ations : also in triangular dodecaedra with their apices deeply trunca- 

 cated. The murio-carbonate of lead is in light green groups of cubic 



i 



