PHYSIOGRAPHY. 



CLASS II. 



3. It occurs in beds of iron-ore in primitive rocks, ac- 

 companied by rhombohedral Lime-haloide, sometimes also 

 by octahedral Fluor-haloide, several species of the genus 

 Augite-spar, rhombohedral Quartz, and axotomous Tri- 

 phane-spar. With the latter, and several species of Kouph- 

 one-spar, it is found in agate-balls and irregular veins 

 traversing trap-rocks. 



4. Upon the beds of iron-ore described above, the varie- 

 ties of Datolite and Botryolite are met with at Arendal in 

 Norway. In agate balls the Humboldtite occurs in the 

 Seiseralp in the Tyrol, in irregular veins in greenstone, in 

 Salisbury-craig near Edinburgh, and in America. 



GBNUS V. KOtJPHONE*-SPAR. 

 1. TRAPEZOIDAL KOUPHONE-SPAR. 



Dodecahedral Zeolite or Leucite. JAM. Syst. Vol. I. p. 

 351. Trapezoidal Zeolite or Leucite. Man. p. 141. 

 Leucite. PHILL. p. 107. Leuzit. WERN. Hoffm. H. B. 

 I. S. 482. Leuzit. HAUSM. II. S. 588. Leuzit. 

 LEONH. S. 459. Amphigene. HAUY. Traite', T. II. 

 p. 559. Tahl. comp. p. 33. Traite\ 2de Ed. T. III. 

 p. 61. 



Fundamental form. Hexahedron. Vol. I. Fig. 1. 

 Simple form. Ci (g) Vol. I. Fig. 34. Irregular 



forms, grains. 

 Cleavage very imperfect, parallel to the hexahedron 



and the dodecahedron. Fracture conchoidal. 



Surface of crystals even, though generally rough, 



of grains uneven and smooth. 

 Lustre vitreous. Colour reddish-, yellowish-, or 



greyish- white ; ash-grey or smoke-grey. Streak 



white. Semi-transparent ... translucent. 



From xcv$9?, light. 



