40 



California Art & Nature. 

 LEUCITE: 



41 



A MONSTROSITY. 



BITTIUM CALIFORNICUM Dall. 



"Shell white, broadly elongate-conic; 

 ■whorls rounded, falling off more abrupt- 

 ly toward the suture than the summit. 

 The earlier whorls increase less rapidly 

 in diameter, and are more evenly round- 

 ed. Base short, well rounded; aperture 

 suboval, eflfuse and subchannelled ante- 

 riorly, with the posterior angle rounded; 

 columella somewhat twisted and slightly 

 revolute. The ornamentation consists of 



about 14-16 broad and low axial folds, 



which gradually become obsolete on the pla};ioclase, magnetite 



The history of leucite is very interest 

 ing. Some 30 years ago Humboldt 

 made the general statement that leucite 

 occurred nowhere outside of Europe. 

 Curiously enough, until within a few 

 years this statement held good. In 1874, 

 howf ver, Vogelsang iound it in an Asi- 

 atic basalt, and in 1876 Zirkel announced 

 its discovery in Wyoming 



'Another extra-European locality for 

 leucite is nuw aninnniced by Von 

 Chrustschoff, who finds it in a lava in 

 the vicinity of the extinct volcano Cerro 

 de las Virgenes in Baja California. The 

 rock consists of an asli-grav ground mass 

 sprinkled with rounded spots of brown- 

 ish-black obsidian or glass, and with 

 light specks of leucite These light 



specks are ^hown by a lens to have a 

 roun<fed octagonal outline. 



'The Kucite is remarkably clear and 

 fresh, and shows in pularized light the 

 well known twining structure, even bet- 

 ter mark e J than in leucite of the Vesu- 

 vian lavas or of the Laacher-See While 

 generally in rounded masses, ths smaller 

 individuals are often clearly octagonal 

 in ouiiin( . The microscope shows the 

 leucite to contain many inclusions, 

 among which are augite, apatite, olivine, 

 nepheline, and 



periphery and base, and on the whorls 3 

 or 4 impressed spiral lines, which are 

 equally apparent on the ribs and inter- 

 costal spaces. This '.species occurs both 

 recent and fossfl in California. Recent 

 shells appear more slender with fewer 

 ribs, 12-14. The type is a fossil 'speci- 

 men from Dead Man's Island, off San 

 Pedro, California, and has eight whorls 

 which measure: long 5.3, diani. 2.2 mm. 

 A recent shell of lo whorls measi red 6, 

 diam. 2.1 mm." — Dall & Bartsch, Nau':i- 

 lus 15:58-59(8 190')- 



CUPRITE — Red oxide of coppsr; red 

 coprer; reported from the Colorado 



desert. 



glass incUisions and bubbles.' — H. 

 Lewis, rep.int in W. Am. Sci. ii. 33. 



C. 



CINNABAR— Composition 86.2 per 

 cent mercury, 13.8 per cent sulphur, 

 weighing 549 pounds per cubic feet per 

 ton. This is the principal ore of quick- 

 silver, and has been reported from 

 Riverside and San Diego counties, but 

 I have seen no specimens in proof. The 

 writer has five specimens from two dis- 

 tinct sources, alleged to have been 

 found in Baja California. The in- 

 dustry in this country is practically 

 confined to California, the product in 

 ISre hrng reported worth over $1.000,COO. 



RUBIDIUM— One of the rare metals, 

 more precious than gold, occurs as a 

 by-product of the lithia mines. 



