JAIC 1986, Volume 25, Number 2, Article 2 (pp. 73 to 81)
JAIC online
Journal of the American Institute for Conservation
JAIC 1986, Volume 25, Number 2, Article 2 (pp. 73 to 81)

TREATMENT OF A SILVER DRAGON FOR THE REMOVAL OF SILVER CYANIDE AND CHALCONATRONITE

Donna K. Strahan


ABSTRACT—Analysis of the corrosion products on a silver dragon suspected to have been treated with cyanide revealed both silver cyanide and chalconatronite. It appears that both of these corrosion products can be formed on silver objects cleaned or replated using a cyanide solution. These corrosion products darken with exposure to light; therefore, they may be mistaken for silver sulfide. In order to determine how to remove the highly poisonous cyanide corrosion product, numerous tests were run. Using a carefully timed procedure the silver cyanide was removed with an aqueous solution of 20% sodium thiosulfate. The chalconatronite was removed mechanically.

Article Sections:

1. INTRODUCTION
2. DESCRIPTION AND EXAMINATION OF THE SILVER DRAGON
3. COMMERCIAL SILVER CYANIDE CLEANING
4. HAZARDS OF CYANIDE CLEANING
5. CHALCONATRONITE
6. TREATMENT OF THE SILVER DRAGON
7. CONCLUSION
1. APPENDIX
a: Appendix , Notes , References
Entire Article

Copyright 1986 American Institute for Conservation of Historic and Artistic Works