Differentiating beween lead and tin?

[Tinkerer]

Today, during discriminating tests with the metal detector I made a strange discovery.
I have some lead musket balls (minies) recovered from various shipwrecks.
When testing with the discriminating MD, I found that some of the lead gives a positive response, and other lead gives a negative response.

Different alloys?

The question is... is it really lead? So I tried some old pewter objects. It seems that fine pewter (near pure tin) gives a positive response and bad pewter (containing more lead) gives a negative response.
So maybe some of the musket balls are made out of an alloy mostly of tin?

Did I invent an machine that can show the purity of pewter?

Has anybody had a similar experience?

Tinkerer

[Max]

Today, during discriminating tests with the metal detector I made a strange discovery.
I have some lead musket balls (minies) recovered from various shipwrecks.
When testing with the discriminating MD, I found that some of the lead gives a positive response, and other lead gives a negative response.

Different alloys?

The question is... is it really lead? So I tried some old pewter objects. It seems that fine pewter (near pure tin) gives a positive response and bad pewter (containing more lead) gives a negative response.
So maybe some of the musket balls are made out of an alloy mostly of tin?

Did I invent an machine that can show the purity of pewter?

Has anybody had a similar experience?

Tinkerer

Hi,
I usually don't care much about lead stuff...but I think you are right: different alloys.

In ancient time lead was always mixed with other metals, either cause of old metallurgy methods or the wish of recovering scrap metal from other sources to give more strenght respect to pure lead.

So I think your idea is right about disc differences due to different conductivity of the alloy than pure lead.

Kind regards,
Max