356 Mineralogical Journey. 
length four feet. Its color was a clean, bluish green for the upper 
three feet of its length, passing into a dull green and yellow at the 
lower extremity. ‘The faces possessed a considerable polish, and 
were quite free from longitudinal striae. A slight irregularity was ob- 
served on a near inspection. The prism had suffered from those ac- 
-eidents which, among strata, are denominated slips ; the effect of which 
had been to give its axis a slightly curvilinear direction. Between 
the sections which had thus been made across the crystal, thin films 
or layers of quartz had been interposed. ‘This peculiarity of strue- 
ture, it deserves to be mentioned, is common to the larger beryls of 
this locality ; and it may be attributed, possibly, to the circumstances 
-under which the rock forming their bed came into its present situa- 
tion. Unfortunately, in attempting to free the sides still engaged, by 
means of a charge of powder in the neighborhood, the concussion 
produced was so great, as to shiver this noble crystal into fragments, 
s6’small as not to allow of its being afterwards set up again. One foot of 
the base, however, came out nearly entire, which is in my possession. 
Its weight is fifty nine and a half pounds, thus giving for the entire 
-erystal the weight of two hundred and thirty eight pounds.* Ihave 
been the more minute in my account of the above crystal, from 
the belief that it is the largest hitherto noticed, notwithstanding 
the testimony of Theophrastus, who mentions having seen one im a 
temple in Egypt, measuring four cubits in length by three in breadth, 
‘and an obelisk of the same gem, forty feet high : both of which are 
justly conceived, at the present time, to have been masses either of 
Verd Antique or Porphyry ; since the early Greek writers are known 
to have called almost every green stone by the name of Emerald. 
».. Two other Beryls, of large dimensions, were also brought to light 
-by the blast. which threw down the one just described ; and there 
can be no daubt that other crystals of a similar size are distributed 
through the rock, at pretty uniform distances, as the Feldspar here, 
‘seems to be replaced almost entirely by Beryl ; which beeomesy = 
-te speak, the equivalent of that mineral, in the composition of the 
granite. A few feet below the spot, affording the larger crystals, 
_\Feldspar begins. to preponderate as) an’ ingredient in, the rock, the 
.Beryls diminish in size as well as. regularity, and present. for 
the most part a yellowish tinge, sometimes passing into deep 
ae ae 
——— 
Be oe Mies 0g tk ie 
14 p. e. for the proportion in which the glucine exists in the Beryl, ie 
s of that rare earth in this crystal. eg an Ge 
