51 



TAB. CCCXXX. 



CALX Fluor, var. arenacea* 

 Arenaceous Filiate of Lime. 



Div. 1. Imitative. 

 Syn. Bab. p. 24. 



Fluor is not only found crystallized in company with 

 Quartz, Sulphate of Barytes, Galaena, &c, in aggregate 

 groups, but detached in very small cubic Crystals scattered 

 in the Lime rock^-see the upper figure, where the Fluor is 

 seen in dark cubes scattered among brown Limestone. 

 Fluor is also found stratified in cubes smaller and smaller 

 until the eye cannot discern them, being in sand-like 

 grains, and finally pulverulent and undistinguishable from 

 their fineness, even passing dendritically among the Car- 

 bonate of Lime or Sulphate of Barytes. The noble-spirited 

 Dr. Jackson, who will always sacrifice the. best of his 

 collection for public use, was so good as to give me a beau- 

 tiful large specimen of this kind with Calamine and 

 Galsena, the latter of which is often found in small de- 

 tached Crystals in the same rock with the Fluor. 



The loiver figure is granular and pulverulent Fluor, re- 

 peatedly stratified with Sulphate of Barytes, which is not 

 very common in an earthy form. Fluor is often of a fine 

 colour when the Crystals are transparent, their transpa- 

 rency often giving great brilliancy to their colour. The 

 middle specimen is a good example of a tolerably fine purple 

 in the granular or dusty form, which form is seldom ad- 

 vantageous to colour. 



The specimens are chiefly from the neighbourhood of 

 Castleton in Derbyshire : 6uch are indeed found in other 

 parts, but not frequently. 



t 2v 



