Identify stone please for my boy.

Second pic reminds me of flint but it’s darker than normal.

Edit: ignore me that’s nonsense.

Despite having an O and A level in geology 1976/78 I can’t help apart from the fact that we used to call them “lucky stones”. Often found in the red shale from iron foundries used in my childhood for driveways and maybe a by-product of the foundries?

Coal

Or baby dinosaur poo

Obsidian? Though that's black not blue. Looks like glass and cracks like glass to leave sharp edges.

I reckon it's probably some kind of foundry slag or waste glass. Unless you happen to live near a volcano?

Possibly Chert. But maybe not shiny enough. I think I agree it may be the by-product of an industrial process. Hard to tell just from the picture. (Geology A-level also)

Most of your classic blue rocks are copper containing minerals and are usually pretty distinctive (although hard to identify exactly). Google azurite, chrysacolla etc for examples.

Slag glass is often cool colours because of all the random elements it contains plus can be swirly or banded. It had that glass texture as it's cooled fast and not really crystallised at all. Note of very slight caution.... maybe don't lick it / handle it hugely as by it's nature it can contain a bunch of heavy metals and other possible nasties.

Where about did he find it OP? I’d agree that it looks like it could be more by product waste than original material.

It was found in Derbyshire. The last strange substance I had the STW knowledge identify on here ended up being slag so I can confirm we don’t have much luck finding anything precious!! I had a big chunk of the very same stone as a kid and my parents convinced me it was Blue John, I remember being so happy and feeling lucky to have found it and kept it as one of my treasures for years 😂

Blue John is really cool but unfortunately I don't think you have some here. Time for a trip to the cave gift shop woop.

Despite having an O and A level in geology 1976/78 I can’t help

Things have moved on a bit since then tbf

It's quite small so it's often called a pebble.
Hth. 👍

I'd agree that it's likely to be an industrial by product but that doesn't mean it's not interesting. You could tell him that "this rock doesn't have an official name as it's very young, but it's formed by a very intense heating process that makes the blue colour and stripes".

If he has more questions, you're on your own.

@pisco that made me chuckle! I don’t think the origins of rocks and minerals formed many, many, millions of years ago has moved on since the seventies!

Looks like slag also. They used to use it for construction purposes like road beds etc so you don't necessarily need to be in an iron making area AFAIK.

<p style="text-align: left;">great to see an enquiring mind at a young age, using the find to think about the importance of provenance to narrow down possibilities, to visit a local museum with geological collections and looking at geological maps, and using these to learn about different rocks and geological eras.</p>

The British Geological Survey app can be useful for this sort of thing - tells you what type of rock you're standing on:

https://www.bgs.ac.uk/technologies/apps/igeology-app/

Or the geology viewer:
https://geologyviewer.bgs.ac.uk/

I’ll stick with my “lucky stone” identification!

Foundry slag. Is it hard and glassy? Can you scratch it with a pin? Does it feel denser than a more usual stone of similar size?

There's a history of copper extraction in the Peak district.

Derbyshire is much more than the Peak District… wide scale lead mining and smelting, lime production, coal mining and large amounts of iron production especially up the Eastern half. There are probably more artificial “peaks” than natural ones!

Identify stone please for my boy.

Not from the photo... and it can be slag as mentioned but really depends how much you want to indulge the lad. Doesn't seem like he's stopping ay time soon... perhaps more interesting if is is flint or obsidian is how it got there... it *could* be flint that was carried there by Palaeolithic people and flaked off a tool whilst it was being made.

On the other side the hydrothermal mineralisation that formed the blue john could make it local and interesting.

It's a conchoidal fracture ...

You can try scratching it .. and get the hardness,
You can try scratching a tile back and get the streak...

etc. but its ultimately a question of if you want to encourage the interest and how far I reckon?

<geologist mode> Sorry, you need a scale bar on those photos. </>