As with Jorgga's first post, I have a hard time believing that these coins have spent just any moment of their life in the ground.
Youtube is full of posts of metal detectors who in their entire carreer do not come near finding even one coin like these. Most of what they dig up are indiscriminable lumps of corrosion. And Jorgga has unearthed three gems in perfectly preserved state within a time span of a few weeks. This story simply doesn't add up.
Are you sure you haven't been metal detecting your grand father's inheritance?
Some coins had that green and Black stuff but few was really good. I dont know why Some were so good and another went Black. These are all at the same area.
Apparently you are very lucky, or you have a very good nose where to detect. Or both.
I apologize, but please take my scepticism as a heads-up: your story and the detected objects just appear too good to be true - you will certainly face more scepticism along the road.
There was estate beginning 15th century. Havent find that old coins yet but good finds as well. Copper coins what i have found is really bad shape. Only two russian coins was good. I found them In sand, not field.
From a chemistry viewpoint,
- anaerobic conditions are more forgiving than aerobic,
- alkaline soils would be more forgiving than acidic ones.
- Cold or dry places more forgiving than warm or wet ones.
- Places NOT downwind from industrial activity would be more forgiving
And so on.
I guess one could be lucky enough to have a few of these come together?