662 MINERALOGY ' 



B. Fused with soda and coal dust in the R. F. on coal it yields a 



sulphur reaction on silver; b, p. 587. 



1. Yields a barium flame (green). 



BARITE, BaSO 4 ; White, blue, yellow, red; Cl. basal 

 and prismatic ; H. 3.5; G. 4.5; F. 4; IV; p. 528. 



2. Yields a red flame (strontium). 



CELESTITE, SrSO 4 ; White, blue, red; Cl. basal, 

 prismatic ; H. 3-3.5 ; G. 3.97 ; F. 3.5-4 ; IV ; p. 530. 



3. It yields a calcium flame (carmine), or a calcium reaction; 



a, p. 566. 

 a. Yields no water. 



ANHYDRITE, CaS0 4 ; White, blue, red, gray; Cl. 3 



pinacoidals; H. 3-3.5 ; G. 2.95 ; F. 3-3.5 ; IV; p. 531. 

 Glauberite, CaNa 2 (SO 4 )2 ; White to gray ; Cl. Basal ; 



H. 2.5-3; G. 2.75; F. 1.5-2; V. 

 Oldhamite, CaS ; Pale chestnut-brown ; Cl. cubic ; 



H. 4; G. 2.58; F. Difficult ; I. 

 6. Yields water. 



GYPSUM, CaSO 4 .2H 2 0; White, gray, reddish; Cl. 



pinacoidal ; H. 2 ; G. 2.32 ; F. 3 ; V ; p. 536. 



c. Yields a yellow flame (sodium). 



Whattevillite, CaNa 2 (SO 4 ) 2 .4 H 2 O ; White; Silky; 

 G. 1.81; F. 1.5-2; Acicular. 



d. Yields a potassium flame through the blue glass. 

 Polyhalite, Ca 2 MgK 2 (SO 4 ) 4 .2 H 2 O ; Brick-red to yel- 

 low ; Cl. pinacoidal; H. 2.5-3; G. 2.77; F. 2; V?. 



Syngenite, CaK 2 (S0 4 ) 2 .2 H 2 O ; White ; Cl. pinacoidal ; 



H. 2.5; G. 2.60; F. 1.5-2; V. 

 Ettringite, (Ca.OH) 6 (SO 4 ) 3 .2 A1(OH) 3 .24 H 2 ; White ; 



H. 2-2.5; G. 1.75; F. 3 ; III. 



C. Fused with potassium bisulphate in the closed tube yields 



a flourine reaction; a, p. 589. 

 1. Yields little or no water. 



a. Will not become blue with cobalt solution. 



FLUORITE, CaF 2 ; White, green, yellow, violet, pink; 



Cl. Octahedral ; H. 4 ; G. 3.18; F. 3 ; I; p. 331. 

 6. Becomes blue with cobalt solution. 



CRYOLITE, Na 3 AlF 6 ; White to brownish ; Cl. pina- 

 coidal ; H. 2.5; G. 2.97; F. 1.5; V; p. 333. 

 Chiolite, 5NaF.3AlF 3 ; Snow-white; H. 3.5-4; G. 

 2.95; F. 1.5; II. 



