FMF - Friends of Minerals Forum, discussion and message board

[SlowFrog]

Hi all!

I found this with my metal detecting pinpointer in a park here in the UK. It was just beneath the soil (about an inch down). I couldn't believe the strength of the signal given how tiny it is (maybe 4mm on the longest side). I initially thought it was iron or lead but after closer inspection - I have absolutely no idea!

It's 0.24g, and doesn't react at all to a very strong neodymium magnet. It does however make my pinpointer scream from an inch away! Any ideas?

Cheers,
John

[SteveB]

Could be a deformed shot ball from old pistol or rifle. Your metal detector enthusiam means nothing as far as identification. It looks man made, could just be slag. UK has LOTS of war history in the ground even back to the roman times where camps sometimes built smelters to make coins and other items but since you’ve removed and cleaned the item its context for archaeology is now gone forever.

[Peter Lemkin]

I agree that the best guess [and without more information it can ONLY be a GUESS] is that is is man-made. However, though that puts it almost out of the realm of this forum on minerals, it could possibly be one or a metallic one that was smelted by humans and of some interest. You should do some tests such as hardness, specific gravity [instructions are on this site, I believe in the 'what is this' subforum]. After that, only some chemical tests could likely tell you what it is. It certainly looks metallic. It also looks to my eye to be man-made or human-modified. There may be more of them in the same area unless it is a old bullet, in which case there may only be the one...... If a bullet, it is misshappen from hitting something or time/weathering/chemical changes in the ground, or something other. Why it is so active on your metal detector one can not say. Some metal detectors can be calibrated for different types of metal, others not. Look online to see what metals and alloys your detector is most sensitive to.

[Poorboy]

Appearances are always tricky, but you should consider "wood tin." I have no idea if cassiterite would set off a metal detector, but it could also be inter-grown with another mineral that is responsible for the signal. Probably man-made, but if it is from the Cornwall area, the odds of wood tin would increase significantly.

[SlowFrog]

Thank you for the replies! For the record, I'm not a detectorist and was out in a playing field with my 5 year old son when I found the specimen - I bought him a $20 pinpointer as a toy to 'find treasure' so we were having fun near the surface of the soil, not digging up significant archaeological sites.

Another person recommended I file down the surface a little as he felt it'd be copper. I did so and I believe he was right! The reddish glassy parts might be some other melted substance (paint?!).

[alfredo]

"Wood tin" does not react to a metal detector, but good quality large shiny black cassiterite crystals do. (I tried this when I was working in Bolivian tin mines.)