Pinging rock advice please

Today I had two types of pinging rock. I usually encounter the black and burgundy slag looking rock with holes in it, that’s nothing new, though today I have a smooth pinging rock with no holes and some flecks in it that I wish were bigger if it’s what I hope it is, the reading swings for it. Tried to get the flecks in the pic, but, alas. Other finds were some current currency I’m going to need to change at the reserve bank and a one cent coin, rubbish ranged from bottle caps, eighties era ring pull tabs to a needle, yep, with the sharp end poking out of rusted sediment. Binned!

1 Like

Interesting, what kind of tone?

Early machine indicating ferrous, to be frank it has a third deep burgundy, almost black vein in it, when wet or oiled the other half is marbled, and non ferrous.
The slag looking lumps I find indicate the iron but nothing else, so it’s something different. Gave up on meteorite theory.

Pyrite inclusions maybe?

I would have to smash it to confirm, in the absence of boil down chemicals, which frankly I wouldn’t know where to start with.
If in the interest of science someone wants to try and is prepared to be honest about it, I’m game, nought to lose really. PM me a postal.

I’ve got access to XRF if you really want to know.

Sounds like hematite, I found a piece very shiny.

PM me a postal and you’ve got a rock experiment.

Magnetic? Does it show attraction to a neodynium magnet?

The slag looking one responds to a fridge magnet. I find lots of them and when kids ask me what I have found I sometimes give them one and tell them to go and check it with fridge magnets. Frankly that slag rock is somewhat of a mystery but given the age of that part of NZ, the odd strange rock from afar is expected.
The smooth rock has been sent for testing so watch this space.

Metal workers, when casting iron or other metals, scrape the crud (slag or dross) off the top of the melted metal and throw it away. There is therefore a great deal of this stuff about since people have been melting metal for various purposes ever since whale hunting days.

That was so long ago I’m calling your reply retro.
That one was (thank you again) tested with few answers, but it definitely wasn’t slag or anything I think is regional so perhaps some random thing that was used as ballast on a now sunk ship.

A better machine since then has meant fewer questions, in fact, I turn Iron off at that beach as there’s too much of it.