C. F. de Landero — Pink Grossularite from Mexico. 321 



bearing on the magnetic question. For the most part they are 

 of a basaltic character* corresponding to the rocks referred to 

 augitite, ■ limburgite and tephrite (?) that abound in small 

 dykes in every Brazilian locality of foyaite with which they 

 appear to have some genetic connection. One contains leucite, 

 the third occurrence of that mineral noted in Brazil. Small 

 basic dykes, totally decomposed, but apparently of the same 

 character, cut the Carboniferous strata at Ipanema. 



Specimens of magnetite ore from various other points in 

 Brazil in the states of Sao Paulo, Minas G-eraes, Sergipe, 

 Parahyba, etc., show inclusions of decomposed mica and apa- 

 tite that suggest a comparison with the Ipanema and Jacupi- 

 ranga ores, and perhaps indicate that the mode of occurrence 

 above described may be quite general. In view of the tend- 

 ency to a schistose structure and transformation into siliceous 

 masses, it may be suggested that possibly some of the jaspery 

 hematites may have had a similar origin. f The only Brazilian 

 magnetite thus far seen that can be definitely determined as 

 having a different origin is from Palmeiras dos Indios in the 

 state of Alagoas. This, which is similar in appearance to the 

 Cumberlandite of Wadsworth, contains plagioclase and augite 

 and is an enrichment of a gabbro. 



Art. XXXVIII. — On Pink Grossularite from Mexico; by 

 C. F. de Landero. 



The occurrence of pink colored garnets at Xalostoc, District 

 of Cuautla, State of Morelos, Mexico, has been known for some 

 years and specimens from there have been preserved in the 

 mineraiogical collections of the School of Mines, in the city of 

 Mexico ; but the locality had not been properly explored, the 

 specimens obtained being merely from the surface. About the 

 beginning of the year 1890, Prof. Urquiza gave me, in the 

 city of Mexico, some of these specimens, better than those I 

 had formerly seen : in August of the same year I gave a few 

 of them to Mr. William Niven, of New York City, the dili- 

 gent mineraiogical explorer. Mr. Niven was so much pleased 



*The exception is the Vergesite described by Rosenbusch (Mik. Phys. Gesteine, 

 2d ed., p. 820) from material sent by Mr. Bauer from the Serra do Hiiario on the 

 divide between the Jacupiranga and Ribeira. This has been traced in a large 

 dyke for over six kilometers. 



\ While there is no evidence of any dynamo metaphoric action at Ipanema 

 affecting the larger blocks of magnetite, they have suffered the martite alteration 

 to such an extent that several European mineralogists who have examined the ore 

 prefer to call it martite or hematite. 



Since the above article was written a dark green spinel (bercyuite?) has been 

 found to be an abundant accessory in the Ipanema magueiite. 



