IOARNAL MINERALOGICAL SOCIETY OF AMERICA 137 Dr' william S. Newcomet described a trip, illustrated with lantern slides, taken while traveling through poland, Switzerland, Austria, and Russia. Details were given regarding the mineral collections seen. Acad,emy phita^d.etphia, of Natural SciencesoJ Nowmber j, 1931. Wvr;o H. Ftecx, Secretary NEW MINERAL NAMES Jarlite Rrcrreru Blcveo: New Minerals lrom Ivigtut, Southwest GreenLand. Med,_ d.elelserom Grlnland,92, No. 8, 1_11, 1933, withl piates. Naur: In honor of Mr. C. F. Jarl. CnBltrcal Pnolnnrres: A fluoride of sodium, strontium and aiuminum: N-a-Sr3AlF16.Analysis (by Ragnar Blix): HzO(-105) 0.0S, HgO(*105") 2.91, F 43.23,Li 0.08, Na 3.23, Mg 0.90, Ca 0.55, Sr 35.60, Ba 0.99, Al t2.t6,Fe0..lI; sum 99'90' Soluble in aluminum chroride. B. B. Fuses easily with eftervescence and gives an alkaline reaction. Cnvsr.rllocnApnrcer. pnopnnrrns: Monoclinic. Forms, o (100), c (001), r (I0l), (110),, m (010).a : b: c: 1.46: 1i 2.58.p : 69"29,. Prrvsrcer. pnolnnrrns: ANo Oprrcll Colorless to slightly brownish. Hd. 3_4, G:3-93. Biaxial,negative (may be in part positive?)a:l.427 , A:1.432_1.433, 2V: 78"10'-80'00'. t:1.435. Occunnnuco: In the cryolite quarries at fvigtut as a dike_Iike formation with barite, partially dissolved remnants of cryolite and gearksutite (?) and thomseno_ lite. w. F. F. Metajarlite Rrcueno Blgvad: Ibid.,pp.7_ll CrrsMrcalPnopnnrrns: Like jarlite. Analysis:HrO (_105) 0.0g,HrO (+105) 2.14,F 45.50, Li 0.04,Na 3.54,Mg 1.38,Ca 320, Sr 28.70,Ba" 2.25, Al 12.49;, Fe 0.31;sum 99.63. Prrvsrcar.ersl Oprrclr. pnopmrrns: Colorgray. Hd. 4_4.5,G.:3.7g0_3.ig1. Biaxial, probably positive. 2y near gO". occunnewcl: ":1.iSZ. Found in individuarsup to 5 mm rong embeddedin chiolite, as- sociatedwith pyrite, topaz, fluorite and ciyolite. MINERALOGIST 138 THE AMERICAN content of-magnesium' calcium and ba- Differentiated lrom jarlite by its higher and by its higher specific gravity' .;-ewhat difierent optical properties ,i";;; i; w. F. F. Igalikite two new mineralsfrom South Green- O. B. Blecrr.n: Igalikite and Naujakasite' 9' 1-7' 1933'with 2 plates' -*-iitt,uni. aa'irtrtrer ombrfnland',vol'92'No From the locality Igaliko, SouthwestGreenland' of-sodium' potassium and alumi- Csnltrcer- P*ott*""s' f iya'out silicate (by Dethlefsen)SiO' 45'85'AIzOs 32'60' num,NaKALSuOrs,2H:O' Analysis: Chr' 6'29, Na2O 5'92' HzO 6'80; sum 99'94' FezOs0.92, CaO 1.41,MgO 0.15, K2O B' B' Fuseseasily (2-3) to a colorless Decomposedby HCI with gelatinization' glass. light brownish' reddish or grayish' Pnvsrcel ANDOPrrcAL Propnnttns: Color but variable' Birefringenceabout that of Streak white. Hd. 5+. G Z'iiS' n:t'SEO oualtczc,r**t""r: interior of a^roundec Found in a singlespecimen as the fine.grained and smaller amounts of biotite' masssurroundea Uy Uartte"ititJ, o"git"' feldspar' apatite and olivine' magnetite, W. F. l-. Naujakasite O. B. Blccrr.o: Ibid',PP'7-12' N.tMs: From the Iocality Naujakasik' oI sodium,iron and aluminum'{zO--' Csnurcnl p*otu*trt.r'A hydtot, silicate 3(Naz,}.e)o.2Aho3.8sio,.a.'uty.i..(byChr.Dethlefsen)Sioz50.95,Alzol20.63' 0'57' cao 0'55' Mgo 0'10' Feo 5.25,N"ro i+'ir, r,ci o'so, Mno Fe2o32.76, a grav- sum99'?4' R' B' Fuseseasilv (about 3) to 11r"girOO"l 1.02, HzO (ign.j z.Oo; ish glass.Decomposed by HCI'p*o"""tins: with gelatinization' monoclinic' pseudohexagonal' Cnvs:t.o.lr,octa"*"ot Probably, p moderatelvinclined {rom atb:c:1.887 tl,z.u- o:ti.osl', b:7 '98L,c:19'5A' 90o.Cleavage micaceous, Perfect' silvery white' on cleavagesur{ace' Prrvsrcer-o"o Ott,ao"-p*onu*t'utt Color grayish. Luster pearly. Brittle' Hd' 2-3' G ' 2'615' normalto the cleavage'p:1'537' Biaxial.2V nearSO'. O";"ptit axisnearly Occunnnltcn:Foundinu'i"gl"specimenasanaggregateofmicalikeplates associatedwith arfvedsonitefrom ranging from 1-3 mm. in diametlr' Intirnately Tunugdliarfik Fjord, SW. Greenland' r,ruiju[u.iL, W. F. F. Correction of monticellite showsa slight er- A redeterminationof the indicesof refraction of the October 1934issue of The Ameri- ror in the gammavalue a';;;;;;"*" 474 can Mineralogist.The new valuesare: d:1.6463 p:1.6535 "y:1 6605 Birefringence: '014.