Something that has been nagging at the back corner of my mind is how copper/bronze ancient coins
survive for centuries in soils of various composition and moisture, with bronze disease
not kicking-in until after excavation.
Perhaps countless millions of such coins have
disintegrated in the soil from bronze disease
over the centuries, while others have not.
Specifically, if FORVM members
include metalugists or similar disciplines, is bronze disease
aerobic? Could it be that it was triggered by finders cleaning the coins in chlorinated water?
Perhaps the answer is "all of the above."
It is very untrue that coins have survived for centuries without damage and 'modern' use of fertilizers have caused problems. Look at the PMS COL
VIMS , a very large percentage of those found are in poor
condition, and they come from areas that are poorly developed or not even used for agriculture
. Even the UK has problems with ancient coins
, and many turned in are from low tech farming.
I have also received coins from deep desert regions that were never used for farming. Fertilizer is mostly nitrogen, more especially ammonia, that is a base, and has little effect on copper based materials.
Take two slugs, or modern pennies, weigh them, put one in straight vinegar, the other in ammonia. seal the containers and let them sit sor 6 months and measure the changes. That would give you an idea.Bruce