Fourth Supplement to Danas Mineralogy, 127 



6. Basal plane of prism, or 0. 



7. Other trapezohedrons (of ■which there are 3*1) whose symbols in Descloi- 



111 



zeaux have the form 6", 6", A", and maj be reduced to those of Nauniann, by 



making :== m^ and = n. 



The "sv'hole number of forms ia 166, of which 62 are rliombohedral. 



New crj'stalline faces, Websky, Pogg. xcix, 296, and von Lang, Pogg. c, 361. Also 

 a paper by V. v. Lang (Sitz, "Wien, xx, 392) on the faint pyramidal markings on 

 pyramidal planes of quartz crystals, in which he refers them to an initiatory trape- 



zohedron which has for the vertical axis y- a. 



Twins of quartz, figured and described by Q. Sella, in Studii suUa Min. Sftrda, 

 Turin, 1856. 



Salt [p. 90, and II, III]. 

 I Kentucky, 1866- 



^ 



Samarskite [p. 356, and II]. — Analysis by Hermann (J. f. pr. Ch., Ixviii, 96): 'Sb 



44-54, Cb 11-82. % 0-50, Mn 1'20, f'e 8-87, C 16-63, Y 13-29, Ce,Ea 2-85. igu. 0-38 

 =100-03. 



Sassolix [p. 144]. — Artificial crystals stated to be monoclinic by Kenngott (Sit- 

 zungsb. Wien, xii, 26), afford the 'planes, /, fT, 0, and are twinned parallel to ti, 

 7:7=118^4', 7: n=l 20° 50'. 



Saussurite p. 264, and II]. — The saussurite of Zobten, Silesia, according to C F. 

 Chandler (Inaug. Dissert.. 1866) is snow-white to greenish-white in color, and has 

 an imperfect cleavage with little lustre, and translucent on the edges. H.=6. It 

 occurs with a blackish-green fibrous hornblende regarded as uralite by G. Rose. 

 Composition ; ^' 



, §i *I 5Pe Ca % ^^a & ign. 



61-76 26-82 1-77 12-96 0-36 4-61 0-62 0-68 = 99o7 



Oxygen ratio for ft, fi, Si. M7 : 3 : 6-lY. G.=2-788— 2-791. Von Rath^s analysis 

 of the saussurite of Neurode gave 1*31 : 3 : 6-12. Mr. Chandler regards the saussu- 

 rit*i as resulting from the decomposition of labradorite. 



Savite fp. 316]. — According to Breithaupt, Savite is trimetric (not dimetric) and 

 7: 7=91° 41'.— Berg, u- Hiitt- Zeit. 1855, 223, in Kenngott's IMLin. Forsch- for 1865. 

 See also under Laumontite. 



ScHOELOMiTE [p. 342]. — Shepard (Shep. Min., 257) makes echorlomite monometric 

 and gives as a figure a dodecahedron with truncated edges. Black garnets occur 

 with the schorlomite, and it seems possible that the two may have been confounded. 



ScoLECiTE [p. 328, and I]. — Dr. Heddle has analyzed the lime-and-soda scolecite 

 called Mesolite, and regards it as a distinct species. The following are his results 

 (Phil. Mag. [4], xiii, 60, and 148) : 



1, Talisker, Skye, 



2, Storr, Skye, 

 8. Kilmore, Skye, 

 4. Naalsoe, Faroe, 

 6. Antrimolite, 



f 



Si 



3tl 



6a 



IS'a 



fi 



46-714 



26617 



9-078 



6-389 



12-831 



46-724 



26-698 



8-902 



5-404 



12*925 



46-26 



26-48 



1000 



4 93 



13-04 



4680 



26*46 



9-08 



6-14 



12-28 



45-98 



26-18 



10-78 



4-54 



13-00= 



100-45 



No 1 is white, in delicate interlacing crystals, called on Skye, cotton stone; 2, ia 

 white and delicate feathery tufts; 3, in yellowish white radiated crystals, forming 

 fiolid masses, resembling natrolitc, affording a prism of 91° and 89° according to 

 Greg ; 4, in downy tufts. . 



Oxj^en ratio of 1, for Na, Ca, Xl, Si, II = 1*38 : 2*59 : 12-46 : 24-27 : 11-40; for 



% H, Si, fi, 1 : 3-13 : 61 1 : 289 = 1 : 3 : 6 : |> in which the lime and soda Lave the 



ratio of 2 :1 or iR^jCa-l-i^^ [approximately]. The proportion of soda present, 

 and the deficiency of water, suggest that the mineral corresponds to 2 of scolecite 



and 1 of natrolite=2[CaSi+il§i+3A4-[Jfagi4-SlSi4-2fl]. [This formula is 

 given for Mesolite by Berzelius in the 4th edition of his work on the blowpipe, p. 

 165 of the German edition.] 



