GeologyRocks

Hi Simon

I don't think it's an alien artifact, merely a piece of flint.  It shows typical conchoidal fracture (bulb-shaped).  Do you live in a chalk area or have you got a neighbour who's just had their drive done?

Hi Gus, thanks for that. I'm not sure if I live in a chalk area or not, and none of my neighbours have had their drive done, maybe someone's throwing stones at my house!

Looks like a 20 pence piece to me!

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

On a more serious note Simon,  its surprising how small stones move around just with peoples shoes picking them up or kicking them (often inadvertantly).

And so much stone of all descrip[tions is moved all round the country (and in from abroad) that future geologists are going to have quite a game sorting it all out. 

I live on Oxford clay, but my house and those of my neighbours have Romsey gravel on the driveways.  In the back garden we have an area of slate chipping - from North Wales and probably Ordovician!

If you visit the coast of Norfolk you will see some huge boulders used as sea defences. The crystal faces (or cleavage faces) tend to give a good reflection at various angles.  It is actually larvikite, and from Norway.

 Sadly I don't think you have found a meteorite.  You say it wasn't there  30 minutes earlier.  In that short time, realistically, it would still be far too hot for you to pick up.

 Sorry to disappoint, but hope our comments help.

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

yup it is a Flint..usually used in the Stone Age as cutting tool as it splits into thin, sharp splinters...