Harder than the tarnish, but softer than the silver, precipitated calcium carbonate could be used in a polish (assisted by Conservator Jacek Wiklo).
Sunday, August 28, 2016
With help from Conservator Ella Gorska-Wiklo, the old varnish was cleaned most efficiently using methylcellulose-based, with particular success on the polished areas of silver. At the same time, the use of aluminum to hold the gel appeared to cause beneficial, electrolytic reduction of the silver, to a certain extent.
Thursday, August 18, 2016
"This Icon was made by special permission of H.M. Nicholas Czar of all the Russias at the Imperial Factory of Moscow for John, 3rd Marquess of Bute who gave it as a silver wedding present to his wife Gwendolen on the 25th Anniversary of their Marriage, April 18th 1897"