IJOHATKS 



2. Yields water. 



Thomsenolite, NaCaAlF.HjO ; White to brown; 



Cl. basal; II. 2; G. 2.93; F. 1.5; V. 

 Pachnolite, Na('aAlF.H 2 O; White; H. 3; G. 2.98; 



F. 1.5; V. 



Gearksutite, CaF 2 Al(F.OH) 3 .H 2 O ; White; Dull; H. 



2; F. 1.5; Earthy. 

 Prosopite, CaF 2 .2Al(F.OH) 3 ; White to gray; Cl. 



prismatic; H. 4.5; G. 2.80; F. Difficult; V. 

 D. Not included above. 



1. Becomes pink with cobalt solution (magnesia), 

 a. Yields water. 



BRUCITE, Mg(OH) 2 ; White, gray, green ; Pearly ; Cl. 



basal; H. 2.5; G. 2.39 ; Inf.; Ill; p. 362. 

 TALC, H 2 Mg3(SiO 3 )4; Apple-green, gray, white; 



Pearly ; Cl. basal ; H. 1 ; G. 2.80 ; F. 5 ; Foliated. 

 6. Yields no water. 



Periclase, MgO ; White, gray, dark green ; Cl. cubic ; 



H. 5.5; G. 3.8; Inf.; I. 



2. Becomes blue with cobalt solution. 



Hydrotalcite, Mg 3 Al(OH) 6 .3H 2 O ; White; Pearly; 

 Cl. basal ; H. 2 ; G. 2.07 ; Inf. ; III. 



3. With Turner's flux it yields a boric acid flame (bright green). 



ULEXITE, NaCaB 5 O9.8H 2 O ; White; Silky; H. 1, 



G. 1.55; F. 1.5; Fibrous; p. 524. 



4. Heated in the closed tube yields iodine. 



Dietzeite, 7 Ca(IO 3 ) 2 .8 CaCrO, ; Golden-yellow ; H. 



3-4; G. 3.70; F. 1.5; V. Green in S. Ph. 

 Lautarite, Ca(I0 3 ) 2 ; Sulphur-yellow to colorless; Cl. 



prismatic; N. 3.5-4; G. 4.59 ; F. 1.5; V. 

 Some silicates may contain enough calcite to yield an 



alkaline reaction after ignition; in general their 



hardness will be above 5 and are not placed in this 



group ; compare the silicates beyond. 



IX. With Turner's flux it yields a bright green flame (boric acid). 

 A. Soluble in HCL 



1. Yields little or no water. 



BORACITE, MgrCUBieOso ; White, gray, green, brown ; 



H. 7 ; G. 2.95 ; F. 3 ; I ; p. 522. 

 Rhodizite, K(A1O) 2 (BO 2 ) 3 ; white; H. 8; G. 3.41; F. 



4.5; I. 



