PETROLOGICAL ABSTRACTS AND REVIEWS 8i 



Washington, H. S., and Kozu, S. "Augite from Stromboli/' 

 Amer. Jour. Set., XLV (1918), 463-69. 

 It is not the intention to give mineralogical reviews in this column. This 

 paper is simply listed to point out the desirability of having at least three 

 things determined in a rock: (i) a chemical analysis of the rock itself; (2) 

 chemical analyses of the component minerals; (3) percentages of the actual 

 minerals present in the rock. It is known that such minerals as the pyriboles 

 and biotite vary in composition in different rocks, consequently to determine 

 whether there is any relationship between the kind of rock and the composition 

 of the component minerals, all of the factors mentioned should be determined. 



Washington, Henry S. "Italite, a New Leucite Rock," Amer. 

 Jour. Sci., L (1920), 33-47. Also a preliminary paper in Jour. 

 Wash. Acad. Sci., X (1920), 270-72. 



Normal leucitites contain nearly as much pyroxene as leucite. Here is 

 described a leucocratic leucitite, containing about 90 per cent leucite, and to 

 it is given the name italite. According to the reviewer 's system it is not quite 

 a true leuco-leucitite (11 20) for it falls just over the line in the second class. 

 The leucocratic minerals amount to 94.01 per cent while in the leucocratic 

 class the line is drawn at 95 per cent. The rock is, however, the one nearest 

 this position that has been found. A striking characteristic is the high per- 

 centage of potash in the analysis, 17.94, or greater by 50 per cent than any 

 previously recorded. 



An ejected block from Monte Somma is also described. This resembles 

 the italite but contains melilite as the last mineral to crystallize. The mode 

 given is leucite 60 per cent, melilite 18 per cent, pyroxene 20 per cent, and 

 magnetite 2 per cent. To this melilite leucitite is given the name veshite. In 

 the reviewer's system it is 2120. 



Washington proposes albanite to replace leucitite for mesocratic types. 



Washington, Henry S. "The Rhyolites of Lipari," Amer. Jour. 

 Sci., L (1920), 446-62. 

 Publishes five new analyses of the Lipari rhyolites, a hyalodacite from 

 Monte Sant' Angelo, Lipari, and an obsidian from the Island of Milos. The 

 following refractive indices, determined by Doctor Merwin, are given: Obsid- 

 ian, Rocche Rosse 1.488-89, from Forgia Vecchia 1.490, from Monte Arci 

 1.487-89, from Milos 1.490, pumice from Monte Pelato 1.499. 



Washington, Henry S. "The Chemistry of the Earth's Crust," 

 Jour. Franklin Inst., CXC (1920), 757-815, figs. 6. 

 Briefly discusses the interior of the earth, mineral and chemical characters 

 of igneous rocks, the average igneous rock, average composition of the earth 's 



