12 PROCEEDINGS OF THE NATIONAL MUSEUM vol.72 



to crj^stallize at room temperature. Eossite was formed when the 

 calcium carbonate was present in excess. The crystals formed in this 

 way are similar in every respect with those obtained by recrystallizing 

 the natural rossite or metarossite. If the synthetic mineral is left 

 exposed to the air it eventually loses water and passes over into 

 metarossite. 



SUMMARY 



Namie. — In honor of Dr. C. S. Ross, of the United States Geologi- 

 cal Survey. 



Chemical properties. — ^A hydrous calcium vanadate, CaO. Y^O^. 

 4H,0. Analysis: CaO 18, MgO 0.14, V2O5 58, H^O 22.90. Sum 

 100.64. Soluble in water. 



Crystallo graphical properties. — Triclinic. a?o = 0.4969, yQ=01%'2A^ 

 ^0 = 0.8295, A=80° 39', /a=59° 31', v=85° 38', a=98° 18', ^=97° 24', 

 y-89° 34'. Habit prismatic. Forms: c (001), & (010), a (100), 

 m (110), 2/(101). 



Physical and optical properties. — Color yellow. Luster pearly to 

 vitreous. Biaxial. 2V large. Plane of the optic axes parallel to 

 the axis c with Z—c. 



a=l.T10, /?== 1.770, y=1.840. Dispersion strong. Hardness: 2-3; 

 specific gravity 2.45. 



Ocaarrence. — Found as small glassy kernels embedded in flaky 

 metarossite at Bull Pen Canyon, San Miguel County, Colo. 



METAROSSITE 



Name. — In allusion to its relation to rossite, a partially dehydrated 

 rossite. 



Chemical properties. — A hydrous calcium vanadate, CaO. VgOg. 

 2H2O. Analyses CaO 20.04; 19.60, MgO 0.10; 0.13, V.Os 64.08; 

 64.20, H,0 13.56; 14.08, Insoluble 2.72; 2.48. Sums 100.50; 100.49. 

 Soluble in water. 



Physical and optical properties. — Color yellow. Luster pearly to 

 dull. Biaxial. 2V large. Dispersion strong. 



a =1.840, /? and y higher than 1.85. Soft and friable. 



Oceurrence. — Found as small veinlets in sandstone at Bull Pen 

 Canyon, San Miguel Canyon, Colo., as a dehydration product of 

 rossite. 



o 



