Removing lichen from lithic artifacts

I am seeking information for our laboratory on the removal of lichen
from lithic artifacts.  We have a number of artifacts that were
surface collected from an archeological site in North Dakota in the
summer of 1999.  They have been stored in paper field sacks since
their collection.  We are looking for direction on how to safely
remove the lichen from the artifacts, if possible.

Carrie F. Jackson

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                  Conservation DistList Instance 13:28
                 Distributed: Tuesday, November 2, 1999
                       Message Id: cdl-13-28-023
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