An examination of the stones which fell at Fort de France showed them to be of a variety of lava called hornblende and andesite.
"Complete Story of the San Francisco Horror"
Richard Linthicum Trumbull White Samuel Fallows
A later series of small diorite or andesite dikes cut the ore bodies.
"The Economic Aspect of Geology"
C. K. Leith
The rock is a much altered andesite and was probably derived from the Arenig district in North Wales, or possibly from a point nearer the Welsh Border.
"Darwin and Modern Science"
A.C. Seward and Others