86 Mr. N. J. Winch on the Geology of 



Fibrous, of a pale pea-green colour, without the pearly 

 lustre of satin-spar ; from Arkendale mines. 



Forming stalactites and stalagmites in all the mines : coat- 

 ing detached crystals of fluor from Allenheads. 



Large quantities of calcareous spar in a state of disintegra- 

 tion, the fragments resemb;:ng bay-salt in size and colour 

 may be observed on the top of Cronkley Fell. 

 Carbonate of Lime. Arragonite. — Flos-ferri. Beautiful specimens of 

 this rare mineral of a snow-white colour and satin-like 

 lustre have been found in Dufton mines. 

 Fluate of Lime. — Earthy, from Breckensyke mine, where the galena 

 is also found partially decomposed. 



In white, topaz and wine yellow, bluish emerald green, 

 and most commonly in violet or purple crystals, having 

 the form of the cube, the cube with its angles truncated, 

 with its angles acuminated by 3 planes set on the lateral 

 planes ; also in tabular and in 24- sided crystals. From 

 Aldstone, Allenheads, &c. 



In small purple cubic crystals, bevelled on the edges, 

 attached to sandstone ; from a mine near New house in 

 Weardale. 



In cubic crystals of a bright emerald green colour, contain- 

 ing drops of water ; from the Weardale mines. 



In a state of decomposition, coated by crystallized quartz 

 purple or blackish in colour, and sometimes appearing 

 as if it had been in a state of fusion ; from Coal cleugh 

 and Aldstone mines. 

 Sulphate of Lime, Selenite. — In 6-sided prismatic crystals terminated 

 by convex planes (Jameson, vol. i. p. 568) on pearl-spar 

 in a state of disintegration ■„ from Aldstone mines. 



