Dating copper found in sand.

Chauncey Gardner

Hi folks,

I'm trying get an age on this bullet.

Specific question is, how preserved/weathered/oxidised would you expect copper to be if an object was buried in a relatively dry sand dune system for say 100 years?

Could it be relatively well preserved such as the attached?

Thanks

Chauncey Gardner

Image

slowburner

A copper bullet?

magicbastarder

would copper not show the classic verdigris patina? unless the OP cleaned that off.

Chauncey Gardner

Hi folks. Thanks for replies.

It’s a lead bullet copper covered, probably a .22 high velocity. Not the sort of thing you use to shoot at cans. I haven’t cleaned it at all.

The issue is we are trying to date it, as it might have been fired at an unofficial firing range, possibly Civil War activity, or it may well be much later. It was found after a slight dune shift along with lots of other bullet shrapnel. (See my post in Military).

Looking at it appears to me to be in too good a condition to be 100 years old.

I was wondering if copper, if deep in sand, wouldn't oxidise as much as air contact was greatly reduced.

slowburner

Corrosion is a product of exposure to air and water.
If the bullet was deep in sand, there is a possibility that it was sealed from the air and the copper might corrode more slowly. The acidity of the sand would have a significant impact too. If the sands are derived from volcanic rock for example, they would corrode the metal more quickly than an environment derived from sedimentary rock.
The state of preservation can not really be used as a measure of age. Is the other material as well preserved?

Chauncey Gardner

slowburner wrote: »

Corrosion is a product of exposure to air and water.
If the bullet was deep in sand, there is a possibility that it was sealed from the air and the copper might corrode more slowly. The acidity of the sand would have a significant impact too. If the sands are derived from volcanic rock for example, they would corrode the metal more quickly than an environment derived from sedimentary rock.
The state of preservation can not really be used as a measure of age. Is the other material as well preserved?

Thanks Slowburner. That's really helpful info, and you raise a very good point.

The bullet image posted on this thread is intact as it "missed" the target and was probably buried deep into the sand.

On my other related post in Miliitary, there are many photos of the pieces of the copper shrapnel casing that are quite corroded and probably did not penetrate the sand as deeply, and the corrosion seems to be at the exposed damaged edges of the copper casing.

I'm not sure of the geology of area but I can check that out.

It's not confirmed but I think we are looking at a possible RIC connection.

For the notebook I've collected these as surface finds and I've been in contact with an archaeologist with the Coubty Council just in case there is an historical interest for them.

Many thanks.

Rosahane

Chauncey Gardner wrote: »

Hi folks. Thanks for replies.

It’s a lead bullet copper covered, probably a .22 high velocity. Not the sort of thing you use to shoot at cans. I haven’t cleaned it at all.

The issue is we are trying to date it, as it might have been fired at an unofficial firing range, possibly Civil War activity, or it may well be much later. It was found after a slight dune shift along with lots of other bullet shrapnel. (See my post in Military).

Looking at it appears to me to be in too good a condition to be 100 years old.

I was wondering if copper, if deep in sand, wouldn't oxidise as much as air contact was greatly reduced.

If it's a .223/5.56 calibre type round I doubt if it's very old. 5.56 was developed in the 1970's and while the other similar calibres such as 220 Swift and 22/250 were introduced in the late 1930's I doubt if there were any in this country until the 1950's at the very earliest.

Chauncey Gardner

Thanks Rosahane.

Here's some more photos which might give you more to go on.

Chauncey Gardner

photos