After reticulation process and pickling in weak sulphric acid....
washed it > under water with soap and rinsed it. after a day or so
there formed a green surface on the ring
G’day Michael; Soap contains sodium stearate, made from a fatty
acid, and although soap is mildly alkaline, a very thin film left on
sterling soon deteriorates back to the fatty acid. This combines with
the copper in sterling to produce copper stearate which is green.
Further pickling would remove copper stearate. Good brushing in warm
water would eliminate this completely.
NOW! I suggest this as something that could possibly occur, but
freely admit that this explanation is but a guess on my part, for I
have not seen anything like this in the books and have not experienced
it. But many people will have witnessed the green colour that can
occur around copper exposed to soap and water, say in a bathroom.
Plausible, no? Oh well… But cheers anyway
John Burgess; @John_Burgess2 of (further away!) Mapua Nelson NZ