New localities of^gate, ^e. 135 



small pieces, is as perfect in its characters as the chalcedony 

 of the Feroe Islands. It is of a delicate gray, translucent, 

 mamillary, botryoidal, stalactitical, or impressed by crystals 

 of quartz, which have usually fallen out ; sometimes these 

 crystals incrust the chalcedony. 



Agates also are found in considerable numbers, both imbed- 

 ded and loose. They usually consist of bands of chalcedony 

 and quartz, and sometimes of the latter onl}^ variously striped 

 or spotted, or interlaced with jasper, carnelian, and cacho-^ 

 long. 



The form of the imbedded agates at East-Haven is com» 

 monly ovoidal, or egg-shaped, and frequently it is conical. 

 Some portions of pure chalcedony occur, which are shaped 

 like a long, slender carrot or parsnip, and the situation of the 

 latter in the ground would exactly represent that of the chal- 

 cedony or agate in the rock. 



The imbedded masses are frequently altogether quartz, and 

 then they are most commonly geodes or hollow balls lined 

 with crystals, commonly very perfect and brilliant, although 

 rarely large. These crystals are commonly transparent and 

 colourless — but they exhibit also most of the varieties of 

 colour which quartz assumes — the amethyst — the smoky — 

 yellow, &c., and occasionally they are tipped and spotted 

 fvith red jasper. 



The spontaneous decay of these trap rocks causes many 

 specimens to be found among their ruins, and many more are 

 imbedded in the solid rock ; but the industry of successive 

 classes from the neighbouring college, issuing from Col. Gibbs's 

 jcabinet, has now made specimens more scarce. 



Woodbury. Twenty- four miles from New-Haven, N.W. 



In a geological sketch of parts of the counties of New^ 

 Haven and Litchfield, which may appear in a future Number, 

 it will be seen that prehnite, stilbite, and agate are found at 

 Woodbury, in the little basin of secondary greenstone which 

 exists there ; the prehnite is abundant — it is not known 

 whether the agates are so, although it is asserted to be the 

 fact ; the stilbite was not observed to be abundant, although if 

 was well characterized.. 



