Fifth Supplement to Dana's Mineralogy. 41] 
was analogous to BaO+S0#. In this sew he xvii, p. i and the Mineralogy 
there 
(p. 502), the writer showed that ear relation in form to Barytes, 
while im resemblance in angles and mono clinic se et to Datholite was very clos 
x “Sats Scheerer published further on the subject (Pogg., xcii, 612, 1854) retaining 
be 
rx Sp 
small io “ie to analyse. 
itly, Scheerer has described the prosopite anew (Pogg., ci, 861). “io 
the follow ving, as a mean ie apa trials (see figure in Min., and this Jour., Xx, 214), 
12: B=76)°, 2: 9=188° 30’, 2: 91=116)9, 25 : 21202 56’, The approxima- 
tion to dao so ies a? ee beet in angles : about equally close, while in wrong 
bit it earer the lat rai Hardne 3 G.=2 890, 28y8. Colorles ns 
Ina ple tabs afturds water - fuorid a icon Decompos »sable by s cnphors ved, 
In the analysis, the fuorid of silicon w as det ined by the difference betw 
total loss in heating a mineral in a Sef stro agents and the amount of pate 
tin heating a mixture of the mineral with wa of lead. eS varpaater thus obtained 
(taking his final vestilel as given in the appendix to his pape 
Al Ca Mn M SiF* it 
4268 22:98 0-81 ose O15 1071 15°50=92°55 
(The potash here intone is cine in oe ee statements of the analysis, but i 7 
overlooked afterwards.) The loss of 757 p.c. is regarde ed as proving that 5 60 
the oxygen is replaced by fluorine. The snindeal is thence supposed to pert ih 
ol ISIF*, 5CaF , 12H, or, differently oi 5X1, LAIFS, ISiF*, 2CaF, 4Ca, 
12H. Scheerer sae out the following formula 
1CaF, Sirs 
1CaF, SiF* 4 X)-olt 
+34 ALF? {seca amano, OF Ga’ ALE? | 4 4GaXl4 (Hf) Al+9H, 
Which he ce is es that of datholite; it may also be added that it is very unlike 
that of Hea y Spar and all other r examples of formulas that we are acquainted 
me and we may welt wait for more lig 
Prropaviurre [p. 803, and I],—Descloizeaux has ogy ( ane d. M,, xi, 261) 
that the bise sll the aphicn at angle is etek to the fre cleava fr and 
tert ie crystallization is not oblique. He makes it crictivia, om the cleavage 
261) 
ERITE [p. 291, and TIT ee to Deseloizeaux (Ann. d. M., xi, 
bon ¢ Kener! Me Siberia, ah oecu violet hexagonal plates on yoiea 
pro WO axes Ps i eble double pe scorites the optic _ quite a ; 
a the bine? rix posit J s it Bs 4 be a mixed mineral, like the Traversella 
F chlorite (see under Delia’ Bette crystals are needed to decide positively as to 
Whether it has o or two optica anes: ‘i 
Prroxe oh to M. de Richthofen (Sitz. Aca 
Vienna, wy 58 a : ae ih comm ia eS edazzo, is a pseudomorph pro- 
the ” 
She tars - sig associated with serpentine in Soe Canada, has 
manne semnetere eke ie o T. S. Hunt (Logan’s Rep. Geol. Canada, 1857, 
P 443). H= G.=3-0 oe Color “celandine- “green. Teena i Contains 
a e-like mineral occurs between the masses of 
iced ip 
