TAB. LXXXIIL 



SILEX Quartzum. 

 Agate Pebbles. 



Class 2. Earths. Order I. Homogeneous. 

 Gen. 4. Silex. Spec. 1. Quartz. 

 Div. 3. Amorphous. 



Syn. Quartz agathe spheroidal. Hauy, v. 2. 423. 



Agate appears to be a very antient name given to this kind 

 of quartzose stone. It is found on many parts of our shore, 

 as at the Bill of Portland, Lowestoft, and on the Welsh, 

 Scotch, and Irish coasts. It is sometimes found inland, 

 about the lochs in Scotland and Ireland ; and, occasionally, 

 in the gravel -pits about London, &c. 



This species has been much admired for its resemblance 

 to many oriental stones ; and differs from our common 

 pebbles by its toughness, which preserves it from large in- 

 ternal flaws. According to its transparency or colour it is 

 more or less valuable, depending on the taste of the owner. 

 Such productions often become pledges of regard, or memo- 

 randums of past hours employed in gathering themj and 

 are thus more esteemed than for their intrinsic value. 



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