The Winona Mine is the northmost 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. 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.
