Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: cfliss on 17/07/2011 22:31:25

Title: Rock Identification, Grand Canyon sample.
Post by: cfliss on 17/07/2011 22:31:25

While on vacation I found this on the side of a small mountain in the Grand Canyon.  The shape of the entire rock was bowl shaped as if it were splattered.  What kind of rock is it?  If it helps the fragment is about 3" long.  The entire find was about 16" diameter and mostly around 1" thick.  There was one other similar nearby.  It is softer than glass and is a bit translucent.  The outer rim and some interior of the find had most of the white crusty rock seen on the left of the photo.  Thank you.

Title: Rock Identification, Grand Canyon sample.
Post by: Mazurka on 25/07/2011 16:39:59

Could well be Travertine, which forms from calcium rich water and sometimes is brown if it carries clay or other sediment.
 

Title: Rock Identification, Grand Canyon sample.
Post by: cfliss on 31/07/2011 16:43:21

That is an idea but does light go through Travertine?

Title: Rock Identification, Grand Canyon sample.
Post by: Mazurka on 02/08/2011 09:14:31

Yes, it can do. 
Practically all travertine deposits are different, depending on how quickly they formed, impurities in the fluid etc.  A degree of translucency is not uncommon.

Title: Rock Identification, Grand Canyon sample.
Post by: Bass on 04/08/2011 05:31:15

Can you scratch it with a knife? does it fizz when acid is applied?