19 



varieties of it, paffing into marly, flinty, Sec. It often affords 

 good crystals. The specimen figured had some little 

 rhombs half relieved on it. A crystallization called, from 

 its resemblance, sugar-candy spar is frequent among it* 

 Shells of various kinds are often found in it. Sometimes 

 it appears in the form of large trunks of trees, hardest with- 

 in, resembling whitish chert. 



Ketton-stone, colour light reddifh brown, lustre o s 

 Transparency o. 

 Fracture earthy granular. 

 Hardness 5 or 6. 



It contains 90 per cent, calx, and 10 of argil. The Bath 

 snd Portland nearly the same in most respects, but harder. 



Spec. grav. Ketton 2*456^ 



Bath 3-494 > Kir. v. 1. 88, 



Portland v^6i) 



