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Geology/Information on green and white rocks


What type of rock are these?
What type of rock are  
Green and  White Rock
Green and White Rock  
QUESTION: Hello Mr. Norris,

    I acquired these green and white rocks from my sisters Indiana home. They are green with white layers and a few dark thin layers as well. It can chip easily and a few of the small ones flake. But they are still a sturdy rock, they were used in a walkway and some were cemented into a raised flower bed since I believe the sixties. I'm thinking they are a sedimentary rock but not sure. Any information will be greatly appreciated.

Thank you,


ANSWER: In order to even make a stab at telling you what these rocks are, I need a little more information. How hard are they: fingernail 2.5, penny 3, iron 4.5, glass 5.5, knife 6.5, file 7.  I need to know what will scratch the rocks.  I also need the streak which is the color that the rock leaves on a porcelain (streak) plate.

The rocks certainly are interesting.


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

QUESTION: Thank you for your quick reply. I tried scratching the rock, the one I am holding in the picture, with everything you listed. I even tried scratching it with an Amethyst I have but it scratched the Amethyst. With the file I rounded the pointed tip of the file trying to scratch it. I tried laying the file flat against the rock and filing it and got a bunch of tiny flakes. I was able to use the side edge of the file to saw a line down into the rock. I used the tiny flakes and crushed them up for the streak test, which the powder from them looked white. I hope this information helps narrow it down.


To my knowledge there are no sedimentary minerals that are above a 7 in hardness.  The mineral is massive which indicates a sedimentary deposition.  It appears to have a brittle habit and a white or clear streak.  This is the first time in ten years of being a expert on All Experts that I could not even make a stab at what a pictured mineral was.  

From the color it appears to be some type of turquoise but turquoise has a hardness of 5 - 6 which means that it could be scratched with a knife blade.

If I were you I would take a piece to a local geology department.  


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Joe Norris


I am an economic geologist. An economic geologist does mineral evaluations and appraisals of mineral or mining properties. I can tell you if your deposit has value - remember that a mineral deposit, no matter how good, only has value when mined. Any value assigned to a mineral deposit, in the ground, is only the speculative value that deposit.


I have been a economic geologist for most of my 35 year career. Although I have done work in perhaps 45 states and numerious countries much of my work has been in Appalachian coal, intermountain west gold and silver, and Arizona uranium.

Past President of the Virginia Section of the American Institute of Professional Geologists and a certified geologist in twelve states.

BS Degree from Eastern Kentucky University. Work on MS Degree @ Eastern Kentucky University, Colorad School of Mines & Marshall University Numerious short courses on the value of mineral deposits and how to value same. Also several short courses dealing with the different types of geologic processes; sedimentary, igneous, metamorphic along with the mineral associated with each.

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