37 

 TAB. CXX. 



S I L E X Granatus, 

 White Garnet. 



Class 2. Earths. Order 1. Homogeneous, 

 Gen. 4. Silex. Spec. Granatus. 



Div. 1 . Crystallized. 



The Rev. John Harriman is the only person from whom 

 I have received this substance, and it has not, to my know- 

 ledge, been spoken of by any author. Indeed its diminu- 

 tive size might almost elude our search, even with the help 

 of the lens. By that aid, however, we can discern in it the 

 modification common to Garnet, viz. the rhomboidal do- 

 decaedron. We must own that the trial of the species was 

 chiefly strengthened by the aid of the blowpipe, under which 

 it resembles the common Garnet, tab. 43 and 44 of this 

 work. These are found in irregular parcels, each crystal 

 being from about the size of a small pin's head to extreme 

 minuteness, sometimes pretty clear and bright, at other 

 times yellowish and of a dirty hue. They have generally 

 well defined sharp facets, which seem to vary but little. 

 They run in lines at the intervals of the divisions in the 

 matrix, which attracted notice by the curious appearance of 

 its yellowish, greenish, light and dark reddish, and brown 

 colours. These Garnets are sometimes mixed among a 

 rough mass of nearly their own nature, which seems to in- 

 corporate with some Quartz. In fusion by the blowpipe 

 they run into a black enamel without addition. The matrix 

 is chiefly Carbonate of Lime, and a siliceous substance re- 

 sembling dull reddish Jasper. 



