What makes this rock like this...?

[curious kat]

....those lines go all the way around it...why please?

 

Amazon Forum Fav 👍

A History of Mining on the Kenai Peninsula, Alaska - Grab it through Amazon!

[TJE]

Ummm...Hard to say if possibly carved or natural kc. (looks carved!)

 

[old digger]

My suggestion is natural weathering, with the softer material eroding more readily. A somewhat common occurrence in layered rock.

 

[curious kat]

It would be exciting if it were "carved" TJE...but think it's maybe natural. It does look carved going all the way around I agree. Is this type of rock "layered" old digger? How can you tell?

 

[old digger]

Is this type of rock "layered" old digger? How can you tell?[/QUOTE]



When looking at it magnified the deeper eroded rings are of a different material (they appear somewhat reddish color) than less eroded material. Yes your specimen appear to be layered.

 

[curious kat]

...OK, thanks old digger...I see what you mean now

 

[Brian T. Booth]

....those lines go all the way around it...why please? <img src="http://www.treasurenet.com/forums/attachment.php?attachmentid=924431"/><img src="http://www.treasurenet.com/forums/attachment.php?attachmentid=924432"/><img src="http://www.treasurenet.com/forums/attachment.php?attachmentid=924433"/>

You have an iron concretion. Either hematite or geothite. There are two ways the rings can form. Old Digger already mentioned one, differential weathering. The other is that the concretion takes the shape of the actual vug (hole) it was created in. great find

 

[curious kat]

Thank you Brian, that information is a great help seems you & old digger have been my "go to guys"...lol