280 Element* of Mineralogy. 



SPECIES XIV. 



Red Calcareous Iron Ore'. 



24. This is found in a loofe form in many 

 'parts of England ; it effervefces ftrongly with 

 acids, and is ufed as a pigment. 



SPECIES XV. 

 Siliceous Iron Ore. 



25. Befides jafper, garnet and trapp over- 

 loaded with iron, there is found, principally 

 in France^ a black, heavy, unmagnetic fand, 

 of the filiceous kind, which is faid to contain 

 iron and zinc in great quantity. 



26. Baron Born, in his letters from Hun- 

 gary, mentions a blue cryftalized iron ore, 



which he fays is a fhoerl overloaded with iron. 



SPECIES XVI. 

 Muriatic Iron Ore. 



27. Serpentine overloaded with iron forms 

 this fpecies, but it is feldom worked. 



SPECIES XVII. 



Martial Calamine. 



28. Calamine is properly an ore of zinc, 

 but fometimes it contains fo large a propor- 

 tion 



