rUh <(/<</ Pm\field — Lanqfordite, \< *</"< /ion it- , eto. L35 



lansfordite. On breaking across the stalactite near the bas< 

 where it seemed wholly altered t<> oesquelionite, it parted with 

 nearly a plane Burface parallel to c, 001. 



N»». L2 is a small end of a stalactite about s""' in diameter. 

 lake the previous one it showed at the time the measurements 

 were made a little of the pa ratline luster of the unaltered lan>- 

 fordite The crystal is highly modified and shows the follow- 

 ing forms: b, 010; <\ (><>f; ,/, 021 ; r, 021 ; M, F10; a>, l32j /a 

 [11; //. nl; o, 112; y, 312; y\ lil; /•, l§2; n, '^; p, 1;: L and 

 10, gl51. These are represented in about their natural size in 

 fig. 14, which is a projection upon a plane at right angles to the 

 vertical axis and which in this case is better than an ordinary 

 projection for showing the relation of the faces. The promi- 

 nent zones which were measured are: />, d, c ami e ; d, x and 

 y ; ( \ o and n ; c, y and M ; q, />, ?\ e, it and p, and r, c, a? and 

 <#, the angles being : 



6 a rf, 010 a 021 = 39° 25' 



(*a c, 021 ^001=44 57 



Ca e, 001 a 021=53 35 



(U x, 021 a 132 = 35 20 



x~ y. 132 a 111=24 15 



Ca o. 001 a M2=33 30 



C/v h. 001 .111=56 38 



Ca y. 001 a 111=52 40 



y.M, 111 a ,10=44 40 



In this crystal we notice for the first time two new pyramids 

 n and p in the zone j?, r, e which has been so prominent in 

 most all of the crystals, we also notice for the first and only 

 time the very steep pyramid w in the zone r, c, x. 



Xo. 13 is a fragment about 19 m,n by ll mm wide, with some 

 rounded surfaces, which was broken from a much larger piece 

 of incrustation ; except for the rounded surfaces the incrusta- 

 tion did not have anything of a stalactitic habit. The frag- 

 ment which was measured separated readily from the rest of 

 the incrustation, leaving angular markings which indicate the 

 juncture of independent and distinct crystals. It was more 

 highly modified than the remaining parts of the incrustation 

 and showed the following forms, b, both 010 and 010; c, 001 ; 

 M, 110 ; fc, §10 ; m, IlO ; d, 021 ; e, 021 ; 0, ii2; n, ill ; x, 132 ; 

 y, 111 ; 2, §12 ; /', 201 ; j), Ill ; r, 10 I2 11, r, 132, 7riS2 and />, 

 I3I. The arrangement of the faces is shown in about their 

 natural size and developement in fig. 15, which is a projection 

 upon a plane at right angles to the vertical axis. The promi- 

 nent zones which w r ere measured are b, M, k and in / c*, and 

 n 1 d, x, y, z, f and m ; b, <7, c, e and b f ; and p, r, r, e, n and 

 p the angles being — 



Am. Jouk. Sci.— Third Serieis, Vol. XXXIX, No. 230.— Feb., 1890. 

 10 



Calculated. 









Calculated 



39° 



16' 



q*p, 



3l2 a 111 = 15° 



20' 



15° 3' 



44 



50 



P *> r, 



111a 132=21 



38 



21 41 



51 



22 



e ~ r, 



021 a 132=23 



51 



24 36 



20 



20 



e a 7r, 



021 a 152 = 18 



21 



20 2 



22 



50 



«Ap, 



021 a!31=32 



36 



33 42 



33 



43 



■K a p. 



l52 a 131 = 14 



15 



13 34 



57 



11 



r a c, 



132 a 001=45 



44 



43 25 



52 



25 



Ca 2, 



001 a 132=44 





43 52 



44 



10 



X a w. 



132 a 5151=35 



16 



35 22 



