We use cookies to show content based on your preferences. If you continue to browse you accept their use and installation. More information. >

FMF - Friends of Minerals Forum, discussion and message board
The place to share your mineralogical experiences


Spanish message board






Newest topics and users posts
04 Jun-13:15:12 Stay at home - coronavirus / covid-19 - magic castle (Jordi Fabre)
04 Jun-10:23:50 Re: collection of annemieke en rob schnerr (Rob Schnerr)
04 Jun-09:05:12 Re: collection of firmo espinar (Firmo Espinar)
04 Jun-08:42:41 Re: collection of volkmar stingl (Volkmar Stingl)
04 Jun-07:04:54 Re: any interesting minerals from ukraine? (Riccardo Modanesi)
03 Jun-15:36:00 Re: collection of sante celiberti - a mineralogical trip through italy (Sante Celiberti)
03 Jun-13:10:03 Re: stay at home - coronavirus / covid-19 (Enrique Llorens)
02 Jun-18:27:15 Re: collection of sante celiberti - a mineralogical trip through italy (Sante Celiberti)
02 Jun-12:40:16 Stay at home - coronavirus / covid-19 - hibiscus (Jordi Fabre)
02 Jun-03:16:14 Re: any interesting minerals from ukraine? (David)
02 Jun-02:04:21 Re: any interesting minerals from ukraine? (Riccardo Modanesi)
02 Jun-01:50:10 Re: any interesting minerals from ukraine? (David)
01 Jun-22:24:16 Re: any interesting minerals from ukraine? (Peter Lemkin)
01 Jun-17:47:51 Re: any interesting minerals from ukraine? (Robert Seitz)
01 Jun-11:16:03 Re: collection of firmo espinar (Firmo Espinar)
01 Jun-06:27:15 Re: any interesting minerals from ukraine? (David)
01 Jun-06:03:02 Re: any interesting minerals from ukraine? (David)
01 Jun-04:01:30 Re: any interesting minerals from ukraine? (Peter Lemkin)
01 Jun-03:34:37 Re: any interesting minerals from ukraine? (Jordi Fabre)
01 Jun-03:14:49 Re: any interesting minerals from ukraine? (David)
01 Jun-00:01:44 Re: collection of volkmar stingl (Volkmar Stingl)
31 May-23:03:51 Re: collection of volkmar stingl (Volkmar Stingl)
31 May-17:20:27 Re: collection of sante celiberti - a mineralogical trip through italy (Sante Celiberti)
31 May-16:31:27 Re: tucson show 2020 (Gail)
31 May-14:27:17 Re: tucson show 2020 (Benj)

For lists of newest topics and postings click here


RSS RSS

View unanswered posts

Why and how to register

Index Index
 FAQFAQ RegisterRegister  Log inLog in
 {Forgotten your password?}Forgotten your password?  

Like
68876


The time now is Jun 04, 2020 15:52

Search for a textSearch for a text   

A general guide for using the Forum with some rules and tips
This rock has me stumped!
  
  Index -> FOR BEGINNERS: What is it? Where is it from?
Like


View previous topic :: View next topic  
Author Message

Tomsalwayssmilin




Joined: 12 May 2020
Posts: 4
Location: North Dakota

View user's profile

Send private message

PostPosted: May 12, 2020 19:12    Post subject: This rock has me stumped!  

I found this rock a few years ago on the edge of a collapsing hillside in NW North Dakota. It's about a foot long and about 9 inches across. Slightly smaller than a bowling ball. It weighs around 10 pounds.

I've contemplated breaking it in half, but if it's going to just be a solid piece of sandstone I'd rather just leave it as is. What do y'all think about it? It's quite interesting to say the least.



FB_IMG_1589298677690.jpg
 Dimensions: 30 x 23 cm
 Description:
 Viewed:  578 Time(s)

FB_IMG_1589298677690.jpg



FB_IMG_1589298682312.jpg
 Dimensions: 30 x 23 cm
 Description:
 Viewed:  593 Time(s)

FB_IMG_1589298682312.jpg


Back to top
Reply to topic Reply with quote
Like
   

SteveB




Joined: 12 Oct 2015
Posts: 124
Location: Canberra

View user's profile

Send private message

PostPosted: May 12, 2020 19:36    Post subject: Re: This rock has me stumped!  

looks like someone poured concrete into one of those speed ball punch bags. The shape, the seams its all there.
Back to top
Reply to topic Reply with quote
Like
   

Tomsalwayssmilin




Joined: 12 May 2020
Posts: 4
Location: North Dakota

View user's profile

Send private message

PostPosted: May 12, 2020 20:28    Post subject: Re: This rock has me stumped!  

Lmao now that you pointed that out it really does look like that. My wife said it looks like a skull. It's definitely not concrete though. I'm almost 100% positive it's sandstone. We have it all over up here and where I found it there were giant pieces of sandstone all over.
Back to top
Reply to topic Reply with quote
Like
   

Bob Harman




Joined: 06 Nov 2015
Posts: 696
Location: Indiana


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: May 12, 2020 20:58    Post subject: Re: This rock has me stumped!  

Identifying rocks only from photos is quite difficult and we prefer minerals to rocks on this website. However blowing up your second photo and scanning the whole surface, I see small remaining areas where crinoid stems and/or archimedes or similar pieces once were.

I believe you have a rounded large cobble of limestone or silicified limestone containing remaining bits of invertebrate fossils. If it is limestone, it will fizz when placed in muriatic acid (28% HCl) for a minute or two. If it has become silicified, that is replaced by quartz, little or no fizzing will occur, but still that is what you have. BOB
Back to top
Reply to topic Reply with quote
Like
   

Tomsalwayssmilin




Joined: 12 May 2020
Posts: 4
Location: North Dakota

View user's profile

Send private message

PostPosted: May 12, 2020 21:09    Post subject: Re: This rock has me stumped!  

Thank you for your response. A lot of the people I had shown it to after I found it thought it was a geode so that's why I thought this may be a good place to ask about it.

I may have to get some muriatic acid and see if it fizzes at all. Thank you for the suggestion.
Back to top
Reply to topic Reply with quote
Like
   

Joseph DOliveira




Joined: 29 Jan 2012
Posts: 233
Location: Hanmer, Ontario


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: May 12, 2020 21:14    Post subject: Re: This rock has me stumped!  

I agree with Bob, it looks like a piece of limestone. The orbicle shape and grooves give the appearance that the stone was worked. It may be possible that you have a native artifact of some kind.
_________________
Joseph D'Oliveira
Hanmer, Ontario
Canada
Back to top
Reply to topic Reply with quote
Like
   

Tomsalwayssmilin




Joined: 12 May 2020
Posts: 4
Location: North Dakota

View user's profile

Send private message

PostPosted: May 12, 2020 23:06    Post subject: Re: This rock has me stumped!  

Thanks for your reply Joseph. I never thought about it being a possible artifact before, but that's also a very good possibility.
Back to top
Reply to topic Reply with quote
Like
   

Mathias




Joined: 01 Apr 2018
Posts: 113
Location: Vlodrop

View user's profile

Send private message

PostPosted: May 13, 2020 00:14    Post subject: Re: This rock has me stumped!  

This looks typically like a rock containing an ammonite fossil inside.
Back to top
Reply to topic Reply with quote
Like
   
Display posts from previous:   
   Index -> FOR BEGINNERS: What is it? Where is it from?   All times are GMT - 5 Hours
Page 1 of 1
    

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


All pictures, text, design © Forum FMF 2006-2020


Powered by FMF