TAB. XIX, 



CALX carbonata, var. margaritacea. 

 Pearl Spar. 



■ 



Class 2. Earth. Ord. 1. Homogeneous.' 

 Gen. 1. Lime. Spec. 2. Carbonate of lime. 



Div. 1. Crystallized, crystal primitive. 



Par. With some iron and manganese. Lustre pearly; crystals 

 often curving. 



Syn. Sparry iron ore. Kir. v. 2* 1 90. 



Spathiger eisen stein. Emmerl. v. 2. 329. Werner. 

 Chaux carbonatee ferifere. Haiiy, v. 2. 175. 

 Pearl spar. Bab. 18. 



Having so distinguished an appearance from other car- 

 bonates of lime, this has obtained the name of pearl spar, 

 a name it naturally suggests, and by which it is in general 

 easily recognized. We find however, like other subjects in 

 nature, it has its gradations, and consequently blends itself 

 with substances to which at first it seems very little allied. 

 It maybe readily traced, as formed from the primitive crystal 

 of carbonate of lime, to an iron ore, consisting for the greater 

 part of oxide of iron, and manganese. The progress, if I 

 may so call it, appears curiously and distinctly marked by 

 the manner of the crystals, which are in the forms of the 

 primitive rhombs, and are white : sometimes however it 

 approaches the appearance of ivory \ and as its substance. 



