Northumberland and Durham. 87 



In slender detached 6-sided prisms, beautifully transparent, 

 often tinged in the central part with a rich orange -red 

 colour ; from Aldstone mines. Mr. Joseph Fryer. 



Salts of Barytes. 



Carbonate of Barytes. Witherite. — In irregular stalactitical minute crys- 

 tals, opake and white ; from Aldstone mines. 



In dodecahedral crystals formed of two hexahedral pyra- 

 mids (Sowerby, tab. 127,) of a pale wine-yellow colour ; 

 from Arkendale mines. 



In elongated hexahedral pyramids or spiculse (Sowerby, 

 tab. 129,) of a chalky white colour; from Arkendale mines. 

 Massive, of a wine yellow colour; from Arkendale. 



Incrusting fragments of galena, blende, and limestone ; 

 white and opake ; from Aldstone moor. 



Forming crystallized balls of a dirty white colour, and 

 striated fracture, radiating from a center. 



In irregular 6-sided prisms without pyramids, and. perfectly 

 transparent, occurring occasionally in the center of the 

 balls above mentioned ; from the WelhOpe mines in the 

 great limestone, where the veins in the upper sills bear 

 heavy spar. 



Of a clove brown colour and striated texture, attached to 

 galena. From Dufton mines. 



Though witherite is the common matrix to lead ore in 

 Arkendale, it occurs only rarely further to the north. 

 Sulphate of Barytes. Heavy spar. — Foliated, Cawk of the miners ; 

 greyish white, opake ; from Aldstone moor. 



In lenticular crystals (Jameson, vol. i. p. 558), cockscomb 



h spar ; from Dukesfield and Aldstone moor. 



