122 



NEW YORK STATE MUSEUM 



Autunite (lime uranite) Ca(IJ0 2 ) 2 P 2 s +8H 2 

 Autunite is a hydrous phosphate of uranium and calcium. 

 It is found in tabular ortkorhombic crystals very similar to 



those of torbernite but lemon-yellow or sulfur yellow in color. 

 It occurs in Connecticut, North Carolina and in the Black hills 



of South Dakota. 



BORATES 



Boracite Mg 7 Cl 2 B 16 30 



Boracite is a chloro-borate of magnesium. 

 The crystals are of the tetrahedral class of the isometric sys- 

 tem and are commonly small and cubic (fig-. 239)>tetrahedral 



Fig. 240 

 Boracite 



(fig. 240), octahedral or dodecahedral in habit; these usually 

 occur isolated embedded in gypsum, anhydrite or salt. A mas- 

 sive variety occurs in snow-white, soft and powdery masses. 

 The crystals are colorless, white to gray, yellow or green and 

 vitreous to adamantine in luster. 



Boracite is found associated with other minerals which have 

 been deposited from solution and occurs in many parte of 

 Europe notably at Sta.ssfurt, Prussia. 



Colemanite Ca 2 B c 31 +5H 2 



Colemanite is a hydrous borate of calcium often occurring in 

 monoclinic crystals, short prismatic in habit, and somewhat 

 resembling those of datolite, also in cleavable to granular and 

 compact masses. Colemanite is commonly white or colorless and 

 of a vitreous to dull luster. 



Under this species are included: 



Priceite. A massive variety, white and chalky in appearance 

 and loosely compacted in structure. 



Pandermite. A white variety in firm, compact, porcelainlike 

 masses. 



