The Winona Mine is the northernmost mine within the
group of datolite producing mines around Rockland and Mass City and the
datolites coming from that mine tend to be white and often with gray copper
inclusions. Some have been found as opaque or with faint color zoning.
It's interesting to note that any mines north of Winona and south of Isle
Royale Mine such as Trimountain, Palesdale, and Baltic seem to be lacking
in datolites for some reason.
