PHYSIOGRAPHY. 103 



Calcareous Spar. 



others; amounting in all to more than forty. Fig. 106, a 

 still more acute rhomboid, the cleavage of whose crystals 

 takes place at the summits, directly upon the edges. It is 

 the mixte of HAUY. ion i=63 44' 55". It is common. P 

 on i=ll9 2' 11". Fig. 107 is the same, having the pri- 

 mary planes at the summit, and having the upper edges re- 

 placed by the planes c?2. Pond2 = 1492' II' 7 , iond2 = 

 149 2' II", i on d'2 154 39' 14". Fig. 108 is the most 

 acute of all the rhomboids of Calcareous Spar. It is called 

 the dilatce of HAUY. It is not very rare, either perfect, or 

 suffering the modifications above described, k on & = 60 

 24'. Fig. 109 represents the primary rhomboid having its 

 upper edges replaced by two planes, the commencement of 

 the dodecahedron with scalene triangular planes, as repre- 

 sented in Fig. 110. m on m over the summit =121 26'. 

 Fig. Ill has the lateral solid angles replaced by tangent 

 planes ; and Fig. 1 12 has in addition, the upper edges of bl 

 replaced by the planes w, which forms the soustractive of 

 HAUY. Numerous other faces, in addition to these, occur 

 in some of the varieties, won 61 = 152 6' 52'', n on n 

 = 161 48' 18". Fig. 113 is the primary rhomboid, having 

 its lateral edges replaced by two planes n. It is very com- 

 mon in this condition ; and with the new planes more ex- 

 tended, as in Fig. 114, it forms the binaire of HAUY; and 

 when they are still more so, as in 115, it forms the meta- 

 tastique of the same author. Fig. 1 13 undergoes more than 

 one hundred modifications. P on n = 151 2' 40". n on 

 n over the summit =48 22'. n on n over the base = 104 

 28' 40". n on n over a pyramidal edge = 144 20' 26". 

 bl on =152 6' 52". 



