184 BULLETIN OF THE ESSEX INSTITUTE. 



quarry of the Rockport Granite Co., Rockport, and asso- 

 ciated with galena at Lynnfield Centre. 

 No. 17. Heinatite : Specular Iron. 



Found on the surfaces of the slickensides of diorite, 

 Salem, in amphibolite at Putnamville, and in hornblende 

 granites, Peabody. 

 No. 18. Hematite, var. Micaceous Hematite. 



Found in the bed rock of the Tophet hill lost gold 

 mine, Lynnfield, Centre. 

 No. 19. Hematite, var. Red Ochre. 



Beverly Cove, Danvers, Topsfield, etc. This is the 

 common anhydrous form. 

 No. 20. Menaccanite : Ilmenite : Titanic Iron. 



Seen in microscopic patches in nearly all of the eruptive 

 rocks, especially in the augite-syenites, diorites and mica 

 schists. 

 No. 21. Leucoxen. 



This mineral, a decomposition product of the titanite, 

 is usually seen surrounding the titanite or entirely re- 

 placing it. 

 No. 22. Magnetite : Iron. 



This occurs in masses in the elaäolite-zircon-syenite at 

 Great Haste ledge, Salem harbor, and is common in crys- 

 tals and small grains in all of the eruptive rocks of the 

 county. 

 No. 23. Chromite : Chrom ic Iron. 



In octahedral crystals in the limestone and Serpentine 

 at the Devil's Basin, Newbury. 

 No. 24. Rutile. 



Common in microscopic crystals in the metamorphic 

 Cambrian rocks in all parts of the county. Larger crys- 

 tals occur in the granites at Swampscott, West Wenham, 

 etc. 

 No. 25. Turgite: Red Ochre. 



