103 



TAB. CLV. 



PLUMBUM carbonatum. 



Straw-like Carbonate of Leach 



Div. 2. Imitative. 

 Syn. Plomb carbonate aciculaire. Haiiy, 3. 483. 



Carbonate of Lead in spiculse is found in some parts 

 of Cornwall, Devonshire, Somersetshire, the county of 

 Durham and other places where Lead ores are found, but 

 the richest specimens are found at Wanlockhead in Scotland. 

 The present specimen is an extremely irregular bundle of 

 fibrous crystals, many of them nearly tubular, curiously 

 formed among ochre which gives it an odd appearance. 

 The spiculae are chiefly formed into irregular columns, 

 something like short pieces of straw. It is upon an Ar- 

 gillaceous Iron Stone with thin veins of Quartz. 



Mr. Laing, from whom we had this, has a specimen 

 with similar crystals seven inches in length, five in breadth, 

 and four in thickness. The crystals are in similar groups, 

 but cemented by amorphous Carbonate of Lead. The 

 entire specimen is of a pure silky white colour. Large 

 as this specimen is, the crystals are not greater than in 

 the one figured. 



