You are here:

Geology/Mineral rock?


mineral rock
mineral rock  
QUESTION: I've found a white/grayish object with very small crystals and pinkish/red objects. Weights about 10 - 12lbs. Need help to identify.. Hope you can help me. I can send you pictures if you like.

ANSWER: Hi Charles,
The pictures I have a very dim and blurry so I can't really make out anything.  You mention a grayish rock with small crystals and red objects.  I can't see any of that, but from what you describe it sounds like a piece of limestone with crystals growing in a vug (hole) or crevice.

Can't tell anything more than that, because limestone will support many different kind of mineralization.  Send a clearer picture with a close-up of the crystals and "pinkish,red objects" and we'll see what we can do.  Also, where did you get this?  Location can sometimes be important in identifying a rock.


---------- FOLLOW-UP ----------

QUESTION: Hi.. Here are the pictures of the pinkish/red objects.  Do you think it maybe a "Phonolite"?  I've found the rock in Chesterfield, Virginia.. I've also been told it is a cow fossil.

Hi Charles,
No images came through so I still can't tell what you have.  

But I can say it isn't a fossil.  

I don't think it's phonolite, but I can't be sure.  Tap it with a hammer (don't hit it too hard).  If it has a metallic ring it might be phonolite, but I don't think there are deposits of that rock type in Virginia.  You might want to check that with a local rock club (here's a list, or a university geology department.   

There is a deposit in New Jersey; could it have been collected from there and found its way to Virginia?

In any case I still can't give you a good idea of what you have yet.  From what little I can see it looks more like dolomite with some crystallization.  Sorry I can't be more definite yet.



All Answers

Answers by Expert:

Ask Experts


C. Robert Reszka, Jr.


I can answer any general geology question (rocks, minerals, stratigraphy, geomorphology etc.). My expertise is in the geology of the Michigan Basin, PreCambrian, Paleozoic and Recent. I can answer questions concerning mining and petroleum exploration and production and the laws concerning those activities. I can also answer questions concerning stratigraphy of the Michigan Basin. I will also answer questions about mineral and rock collecting in the Basin. I won`t be able to answer many specific questions on hydrology, geophysics or geochemistry. I may be able to answer very general questions in those venues.


I have been working for the State of Michigan for 36 years as a Geologist and a Resource Analyst. I have experience with Subsurface Geology and Petroleum Geology, mining in Michigan, and Sand Dune Mining and Protection issues.

Michigan Basin Geological Society

Decade of North American Geology.
Bedrock Geology of Michigan

BS Wayne State University

©2017 All rights reserved.