[Nhcoll-l] amber vs. naphthalene

[Janet Waddington]

I'd be very cautious about planning to store amber where it may be exposed
to vapour phase biocides.  See our preliminary study from 1988 and 1990.

 

Qualitative study

Preventive conservation of amber: Some preliminary investigations

Janet Waddington and Julia Fenn

Collection Forum, 4(2), 1988, pp. 25-31

 

Quantitative study

Infrared spectroscopic analysis of Central and South American amber exposed
to

air pollutants, biocides, light, and moisture.

R. Scott Williams, Janet B. Waddington, and Julia Fenn

Collection forum, 6(2), 1990, pp. 65-75

 

Discussion

Specimens exposed to naphthalene, camphor, or paradichlorobenzene
individually

showed no visible alteration but in combination they caused cracking and

severe softening of both old and new surfaces. IR spectra of specimens
exposed

to a mixture of all three show that all are absorbed (Fig. 6). Although
these vapour

phase biocides seem to cause little or no chemical damage, the problems
caused

by prolonged softening (dust adsorption, loss of surface gloss, and possible
surface

sag) make their use either as insect repellants or corrosion inhibitors
unacceptable

where amber is stored.

Conclusions

Preliminary data suggest that amber can best be protected by 1) eliminating

ultraviolet light; 2) avoiding contact with vapour phase biocides and
corrosion

inhibitors (especially in tightly closed containers where the vapour
concentration

can reach high levels); and 3) maintaining a stable moderate humidity at
room

temperature. Although several vapour phase biocides cause softening and
other

damage to amber surfaces, Phostoxin had no apparent effect on amber. Amber

specimens that appear undegraded and intact may have weakened and friable

surfaces, and therefore should be displayed only in soft, shock absorbent
support

systems.

 

Janet Waddington

Departmental Associate, Natural History

Royal Ontario Museum

janetw at rom.on.ca

 

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