[NHCOLL-L:2061] Question

[Ron Harvey]

I am posting this question for a fellow conservator:

I am looking at appropriate storage for opal jewelry and wondered if anyone
out there has dealt with this in the past.  I've been unable to locate any
literature that addresses what "they" say; store opals in water or oil lest
they lose their brilliance permanently.  The opals in question here have
been stored in semi-sealed conditions for many, many years and retain their
brilliance.  I am assuming that their "microclimate" was not perfectly
sealed, bringing the interior of the cases into line with the RH in the
storage room.  (The case was opened for inventory purposes before I surveyed
the pieces so I have no idea what the long-term RH was.)  The typical RH
range here is 4% to 35%.  This implies to me that dry conditions will not
affect the brilliance of an opal.  Still, I am uncomfortable not knowing
exactly what's going on in the stone.  

I'd appreciate any insights on the relationship between brilliance and
moisture content.
Thanks,
Teresa Myers

__________________
Teresa Myers
Conservation Department
Museum of New Mexico
(505) 476-1239
tmyers at mnm.state.nm.us