Pigment instability

Can anybody shed any light on the problem of colour instability
in certain pigments, notably red mercuric sulphide (vermilion),
tetroxide of lead (red lead), and lead carbonate (white lead), under
Q-switched YAG laser radiation (wavelength 1064nm)?

Christopher Weeks
Amiens, France

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                  Conservation DistList Instance 9:18
                Distributed: Wednesday, August 23, 1995
                        Message Id: cdl-9-18-002
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