476 



LARSEN AND HUNTER: ME LI LITE 



The following analysis (1) was made by W. T. Schaller in 

 the laboratory of the United States Geological Survey. Analysis 

 (2), which is of melihte from Capo di Bove, Italy, is given for 

 comparison. 



TABLE 1 



1. Melilite from Beaver Creek, Gunnison County, Colorado. W. T. Schaller, 

 analyst. 



la. Analysis computed free from apatite, calcite, magnetite, and perofskite. 



2. Melilite from Capo di Bove, Italy. Bodlaender, analyst. 



1 BaO and SrO were not determined. The melilite rock contains 0.28% BaO 

 and 0.35% SrO and this is believed to be in the melilite. 



Alteration. Two types of alteration of the melilite have been 

 recognized, and both are beUeved to be due to contact meta- 

 morphism. In the more common type the melilite is altered to 

 a very fine aggregate of garnet, diopside, and vesuvianite, with 

 some calcite, zeolites, and several undetermined minerals. It 

 appears to be a recrystallization of the melilite, probably without 

 important additions or subtractions of chemical constituents. 

 In the less common type the melilite is altered to a fibrous aggre- 

 gate of a new mineral — cebollite, described in the following paper. 

 The alteration begins along the cleavages and seams in the meli- 

 lite, spreads out, and finally replaces all of that mineral. Melilite 



