NO. 1392. THE MOUNT VERNON METEORITE— TASSIN. 217 



in color with a metallic luster; nonmagnetic; have a specific gravdty 

 of 4.49 at 18'-' C, with the following composition: 



Chromic oxide (34. 91 



Alumina 9. 85 



Magnesia 4. 96 



Ferrous oxide 17. 97 



Silica 1. 38 



Olivine occurs in more or less rounded masses which, when care- 

 fully extracted, show well-marked facets. These facets are prohably 

 not to be referred to any crystal forms, since no zonal relations could 

 be established after repeated measurements. The mineral is com- 

 monl}' ])rownish in color and only occasionally honey yellow. The 

 ble))s are more or less cracked and the cracks tilled with foreign mate- 

 rial, as graphitic iron, limonite, chromite, etc. Some of the clearest 

 grains, which under the glass were cpiite free from impurities, were 

 selected for anal3\si.s, with the following results: 



Silica o5. 70 



Magnesia 42. 02 



Ferrous oxide 20. 79 



Ferric oxide 18 



Alumina 42 



Manganese 14 



Nickel oxide 21 



Phosphorus Trace. 



