I’ve just found in the dirt under our old house (while removing the floors) a 1919 penny. It appears to be bronze but is very discoloured (green) and battered. Does anyone know anything about this particular coin, are they common? Also, how do your go about cleaning such a coin (or do you leave it as is)?
New to this community, so any advice/inforamtion gratefully received.
The discolouration is oxidation of the copper caused by damp air or soil and this turns the copper into Malachite. This basically means that the coin has a thin layer of malachite where the copepr has oxidised.
This being the case the coin cannot be brought back to its pre lost condition and will never have any collector value except as a curiousity but in its own right has character and is a great wee treasure to have found.
Leave it as it is except a clean up in soap and water - NO abrasives, polishes or other nasties like sand paper! Coins can be cleaned in olive oil but int he case of a coin with a malachite oxidation it wont make toomuch difference.
Wow - thank you for that information. I’ve cleaned it up in warm soapy water so will leave as it. We also found some very interesting bottles (blue bonningtons irish moss) and a very old womens leather boot - some cool treasures for sure!
If you can put some phoptos of the bottles on - torpedo and marble bottles are ACE - blue bottles are also ace - some bottles are quite valuable as well, especially cottage ink and scarcer marble and torpedo bottles.
Cool. Always nice to find something under a house that adds to its story.
Could always seal them up inside a wall for future DIY delight 
I’ve found some pretty interesting items inside of walls,ceilings and floors in my 30 years of building,worked on a 17th century vicarage in England and found a hand written receipt for coal payment inside a wax paper envelope signed and dated 1713 in perfect condition like it was written yesterday,ink still looked wet.Made a glass case for it for the owner.
But the kicker was an old sparky from Nelson way who found a satchel stashed in a chimney breast cavity with 100’s of ounces of fine flakey gold in it,he said he gave it all back to the elderly owners,who reckoned it came from the wife’s father who used to mine in the area way back,man did he find the mother of all pay streaks!!
I reckon I have lost way more punches,chisels and pencils than treasure I’ve found.
Them"s the breaks!
Our last house has a camera inside the wall - unintentionally. At least that’s the only explanation we have for it’s disappearance. Hopefully the finders will still have the ability to develop 35mm film!
Current house has several generations of cellphones in the wall, as phones die/get replaced we drop them down inside the framing - right back to an 80’s one that looks like a military field telephone. Must be 8 or ten in there now. Collectables in thirty years. LOL