• Register


Information for users from the old Q&A site
If you have an account from our old Q&A site, your account was transferred over, but you need to reset your password and confirm your email address.
Reset Password here
Confirm Email here

2,064 questions

3,569 answers

946 comments

14,282 users

Is this a rock?

0 votes

I found this in the bed of the Mad River in northern California.  My guess would be that its some sort of quartz deposits on a sandstone, but that is just my novice guess.  Those little bubble like forms have the white inside and that is why I thought they might be quartz.  It is about 8 1/4 inches.  I liked the shape so brought it home to add to my collection but would like to know a little bit more if anyone can help.

asked Aug 29, 2016 by April (180 points)

1 Answer

0 votes
Rocks and sediment and water combined to make a rock which is called a concretion.
answered Aug 30, 2016 by Weasel (52,110 points)

Related questions

0 votes
3 answers
asked Sep 12, 2017 by robuster91 (140 points)
0 votes
2 answers
0 votes
1 answer
asked Aug 31, 2015 by Shawnmccauley78 (120 points)
 


...