47 



of alternately clear and opaque substance. From its sides (not 

 from the corners) radiate brush -like opaque lines forming a 

 star of six rays. Outside of this hexagon the section is clear 

 and free from inclusions nearly as far as the outer edge, where 

 there is again an opaque zone of the same character as the 

 foregoing. From its sides rays shoot inwards meeting the rays 

 of the central star. These phenomena probably are of a second- 

 ary nature and due to alteration of the mineral. 



The hardness of cordylite is = 4,5 (the mineral easily 

 scratches fluorite, but not apatite). It is rather brittle; frac- 

 ture conchoidal. Parallel to the base there is a very distinct 

 cleavage. In this direction the crystals easily break, and the 

 above described structure is often microscopically observable 

 on the cleavage plane. 



By weighing in benzole the specific gravity of the mineral 

 was found to be = 4,31 (Mauzelius). 



Before the blowpipe, cordylite behaves as follows. When 

 heated alone it decrepitates violently cleaving into thin plates 

 along the basal cleavage. In the most intense heat the 

 splinters become brownish in colour, but do not melt. Moist- 

 ened with hydrochloric acid they colour the flame green. 



The mineral is easily soluble in hydrochloric acid with 

 the evolution of carbon dioxide. 



As only a very small quantity of cordylite has been found, 

 the amount that could be procured for the analysis was rather 

 scanty. Nearly all the specimens at hand were scraped, and 

 the impure material thus obtained was subjected to a tedious 

 process of collecting under the magnifying glass. In this way 

 0,6489 gr. of almost pure material was obtained. This material 

 was divided into two portions, the carbon dioxide being deter- 

 mined on 0,2501 gr. and the other constituents on the remain- 

 der. The analysis has been performed by R. Mauzelius, 

 and the result is as follows. 



