GeologyRocks

Hello Elke,

Nice to see you back on here.

I don't think these have been 'made',  I think the fractures are natural. 

A complete guess (on colour and bits in it ) is that this is a ryolite (intrusive igneous) and the angles you see are a sort of columar jointing (like Giants Causeway for instance, except that is a basalt) or it could be the result of a process known as freeze/thaw - which is exactly what it is.  Water freezes at night, expands the crack, fills with more water, more freezing and eventually cracks the rock.

  John

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

I have found the pieces in an aerea, where stone tools have been found as well as as clay pieces from  early copper melting furnaces (connetion from bellows to furnace).  And I habe looked at several pieces. Some of them were definetly not tools or man made. And it is amazing how they fit into he hand.   Well, it is nice to belive they are tools ...

What was missing before was any sort of scale, but you have said 'they fit in the hand'.    However, I am asking myself what they could have been used for if they are tools.  Generally, stone tools would be used for cutting or hammering.  The edges don't look sharp enough for cutting, and there are no chips off where hammering has taken place.

If copper was smelted there  they may have cracked that shape because of the heat and some rocks go very red when they have been exposed to intense fire heat.  Maybe these pink ones were exposed to a lesser heat, or not have the necassary chemical signature to go fully red.

John

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

The round one could have been a grindstone. And I think it is important to consider other possibilities like the ones you have mentioned before.