Tenth Supplement to Dana's Mineralogy. 



giving the oxygen ratio for ^, Pe fi, 10: 12: 7, or 2(Pe 'My-'P+I^-Cowptes 



Engelhardite.—See ZrRCO>f. 



Epidotk [p. 206, II-VIl. IX].— Dr. Genth has described an interesting variety of 



B^n oTll^ery "rysta'lT'somrcrystl^^ H aVd J." CleuvaffC 



Tlie lar^^er crystals are frequently intermixed witii clialcopyrite, pyrites and quartz. 

 Analyses No. 1, by Genth, No. 2, by Trippel, of a coarse grained, confusedly crys- 



^ ^Si Si Pe lEln Ca % Cu K T§5''_gg.,^ ^^^^^ 



Other partial analyses are given~(thi3 Journal, [2]. xxxiii, 197). 



FF.I.DSPAR [p. 228, I-III, IX].— S. D. Hayes baa investigated tbe properties of 

 fused feld-par (Poqq. ^rm.,cxiii, 468). His results show tliat feldspar sutlers no 

 material change in its composition by fusion. [It is well known that leldspar is 



Clauslhal'L!ib!ratorv% see b!'uvTiI. Z^ilung',xx, 265. Analysis of gla>ii>y feldspar, 

 from Lowenburg by G vom Hath. Zeitiwhr. Geol. Gese/hch., xii, 44. For other 

 analyses, see KenngJtt, Uebersicht, 1860, 63-65. 



FiCBTELiTE fp. 472, VI— T. E. Clark shows the crystals of this resin to be mono- 

 clinic. The crystals obtained were from a solution in alcohol and ether {An7i. d. 

 Chm. u. Pha,L, cxix, 226). 



TTl -Th^ M\i\ i}nor from "Wolsendorf, in the Palatinate, in 

 e (Min. 94), has 

 ?n, xli). who an- 



"Iver. ■ Analysis by Von Fayr : 



27'l 18^1 stSs 3^o'7 0^63 = 10000 



^K 1859, p. 51-56, in Jahrb. Min, 1860, 579. 



finJ3 that they possess no trace of cubic cleavage, but that they have a perfect basal 



