Name:  Serpentine

Geologic Name:  Glenarm Serpentine

Reference:  Johannson, Albert: The serpentines of Harford County,
Maryland: Maryland Geol. Survey, vol. 12, p. 219-254, 276-7, 1928.

Microscopic characters:  The slide is composed chiefly of serpentine
(antigerite and serpholite) and carbonate (magnesite mostly).  
Clusters of small magnetite grains and occasional subhedral pyrite 
grains are present.